# Extensions Market

> Extensions Market is an indie software studio founded by Vladislav Gerasimchuk (San Francisco, CA) that builds Chrome extensions and Shopify apps. Every tool was built to solve a problem the founder ran into personally. All products are free to start with optional paid upgrades. Contact: contact@extensionsmarket.com

## About the Founder

Vladislav Gerasimchuk is an indie developer based in San Francisco, CA, who builds focused tools for professionals — home buyers, car buyers, Airbnb hosts, STR investors, job seekers, sales teams, and Shopify merchants. Each product solves exactly one problem and does it better than anything else available. Extensions Market has no investors, no outside funding, and no team — just one developer who uses the tools himself daily.

## Products

### Free Web Tools

- [All Free Tools](https://extensionsmarket.com/free-tools): The hub page listing all ten free web tools, grouped by job: Shopify inventory and operations (Stocky converter, product CSV checker, stockout cost calculator, days-of-stock calculator, supplier price reconciler), store health and growth (store audit, AI shopping readiness checker, checkout deadline checker, Google Merchant Center compliance checker), and AI and content (AI text detector). Every tool is free with no signup and stores nothing. Start here to find the right one.
- [AI Detector](https://extensionsmarket.com/free-ai-detector): A free, no-signup AI content detector that runs entirely in the browser. Paste any text to get a 0-100 human-read score, a verdict (likely AI-written, some AI tells, or reads human), the exact flagged AI phrases and buzzwords, the structural writing tells (uniform sentence length, low word variety, decorative em-dashes, hedge stacking, repetitive openings), and a free one-click clean-up that swaps common AI phrases for plainer wording. No text is uploaded or stored — the analysis is local. Free and unlimited. Pairs with the Anti-Slop Chrome extension for checking and rewriting text on any page.

- [Free Shopify Store Audit](https://extensionsmarket.com/free-shopify-store-audit): A free, no-signup tool that audits any Shopify store from its URL. Checks page speed and Core Web Vitals (via Google PageSpeed), SEO essentials (title, meta description, canonical, H1, robots.txt, sitemap), mobile setup, product structured data, third-party app/script bloat, and conversion gaps (social proof, urgency, reviews, bundles, email capture). Returns a 0-100 score per category, a prioritized issue list, and app recommendations mapped to the gaps found. Auto-detects Shopify. Reads only the public homepage; nothing stored. Free and unlimited.
- [Free Stocky Export Converter](https://extensionsmarket.com/free-stocky-converter): A free, no-signup browser tool that converts Stocky exports into clean, import-ready files before Stocky shuts down on August 31, 2026. Handles Stocky purchase orders (CSV or the Stocky API JSON), suppliers, stocktakes/inventory counts, and SKU/cost lists — auto-detecting each file. For purchase orders it consolidates Stocky's one-PO-at-a-time exports into a single file and preserves status, received quantities, costs, dates, and supplier — the history Shopify's native import drops (Shopify's PO CSV only creates a new draft with line items). Outputs a Shopify-native CSV where Shopify supports it (inventory SKU+Available, cost-per-item) and an EZStock-ready file that imports full PO history in one step. Rows Excel mangled or with a blank SKU are listed, not silently dropped. Runs entirely in the browser; nothing uploaded or stored. Free and unlimited.

- [Free AI Shopping Readiness Checker](https://extensionsmarket.com/free-ai-shopping-checker): A free, no-signup tool that checks whether AI shopping agents (ChatGPT Shopping, Google AI Mode, Perplexity, Gemini) can read and recommend a product. From a product page URL it grades six signal groups: product identity and data (Product schema, price, currency, availability, brand, a GTIN/MPN/SKU, breadcrumbs), reviews and authority (AggregateRating schema, review count, visible ratings), merchant trust (Organization schema, return policy, shipping, warranty), buyer-question coverage (specs/attributes, FAQ, description depth), commercial data hygiene (machine-readable price, canonical, Open Graph product tags), and AI crawler access (whether GPTBot, OAI-SearchBot, ClaudeBot, and PerplexityBot are allowed in robots.txt). Returns a 0-100 readiness score, per-signal pass/fail, and specific fixes ranked by impact. It is a fast rules-based read of the public page and its robots.txt — it does NOT call ChatGPT or any AI model and stores nothing. Works on any store (Shopify, WooCommerce, custom). Free and unlimited.

- [Free Shopify Checkout Deadline Checker](https://extensionsmarket.com/free-checkout-checker): A free, no-signup tool that checks a Shopify store's exposure to the 2026 checkout extensibility deadlines. Key dates: Shopify Scripts stopped running June 30, 2026 (custom discount, shipping, and bundle logic must move to Shopify Functions); the Additional Scripts field was locked August 28, 2025 (broke legacy Meta and Google tracking at checkout); legacy checkout.liquid is hard-blocked August 13, 2026 for Plus and removed for all stores by August 26, 2026, after which unmigrated stores revert to a default checkout. From a store URL it scans the public storefront HTML for legacy tracking still injected inline (Meta Pixel fbq, Google Analytics/gtag, Google Tag Manager, legacy purchase dataLayer, other ad pixels) versus the migrated Shopify Web Pixels manager, and returns a score, ranked findings with why and fix, plus a dated admin checklist for the parts that can't be seen remotely (the Settings > Checkout "Upgrade" button, live Shopify Scripts, the Additional Scripts field, order-status and checkout.liquid customizations). It is a fast rules-based read of one storefront page — it does NOT read your actual checkout page (that is behind the cart and login), does NOT call any AI model, and stores nothing. Free and unlimited.

- [Free Shopify Product CSV Checker](https://extensionsmarket.com/free-shopify-csv-checker): A free, no-signup browser tool that checks a Shopify product import CSV BEFORE you upload it, catching mistakes that Shopify imports without an error but that break or delete data. The most important check: if a product CSV includes a SKU or Weight column but not BOTH the Option1 Name and Option1 Value columns, Shopify's import creates a new default variant and deletes your existing variants — the file looks valid and imports silently, and you lose your variants. The tool flags that exact case, plus SKUs mangled by Excel into scientific notation (e.g. 7.05E+11, which permanently loses the real SKU), blank or malformed handles that split one product into several, prices with a currency symbol or thousands separator that import as 0.00 (use 9.99 not $9.99), image URLs Shopify can't download (http-only, login-gated, or filenames ending in _thumb/_small/_medium), and encoding problems like a UTF-8 BOM that hides the Handle column or CRLF line endings. It returns a worst-first verdict (critical / error / warning / clean), each finding with why it matters and how to fix it, and the exact affected row numbers. It reads only the CSV you provide, entirely in the browser — it does NOT connect to your store, compare against your live catalog, test image hosts, call any AI model, or store anything. Free and unlimited.

- [Free Stockout Cost Calculator](https://extensionsmarket.com/free-stockout-cost-calculator): A free, no-signup browser tool that estimates the revenue a Shopify store loses while a product is out of stock. Enter units sold per day (before the product went out), price per unit, days out of stock so far, and optionally days until restock. It computes lost revenue per day (units per day x price), total lost so far (lost per day x days out of stock), units not sold, and projected loss by the restock date, and shows a live counter of the loss climbing in real time. The core formula is: lost revenue = units sold per day x price per unit x days out of stock. It measures the direct lost revenue, which is the part you can put a number on; a stockout also has indirect costs (customers switching to a competitor, lost repeat orders, and lower search/ad placement for a sold-out product). Runs entirely in the browser; nothing is uploaded or stored. Free and unlimited. To prevent stockouts, set a reorder point and watch days of stock left based on sales velocity — the EZstock inventory app tracks this and warns before a product runs out.

- [Free Days of Stock Left Calculator](https://extensionsmarket.com/free-days-of-stock-calculator): A free, no-signup browser tool that works out how many days of stock a Shopify product has left and when to reorder. Enter units in stock, units sold per day, and optionally supplier lead time. It computes days of stock left (units in stock / units sold per day), the projected stockout date, and a reorder-by date (stockout date minus lead time) so a restock arrives before you run out. The core formula is: days of stock = units in stock / units sold per day. It shows a runway gauge that recolors from healthy (more than 30 days) to reorder-soon (8 to 30 days) to critical (under 8 days). The key point it teaches: reorder before your days of stock left drops below your supplier lead time, or you sell out while waiting for the delivery. Runs entirely in the browser; nothing is uploaded or stored. Free and unlimited. EZstock calculates days of stock left for every product from real sales velocity and sorts the dashboard by urgency.
- [Google Merchant Center Compliance Checker](https://extensionsmarket.com/free-merchant-center-checker): A free, no-signup, zero-AI tool that audits one Shopify product page for Google Merchant Center misrepresentation and suspension risk. Paste a product URL; it fetches the page and reads all Product structured data (JSON-LD), meta tags, and the visible price and stock, then runs 10 rule-based checks in three categories and returns a 0–100 risk readout (inverted, so a high score means low risk) plus a risk level of Low, Elevated, or High. The headline check keeps every Product JSON-LD block separately and flags a conflict when your theme and an SEO app both emit Product schema with different price, availability, brand, or identifier — so Google is told two different stories about one product, the top cause of a misrepresentation strike. Other checks: GMC-required Offer fields (price, priceCurrency, availability, brand, and a gtin or mpn identifier); shippingDetails and hasMerchantReturnPolicy in the Offer; price mismatch between your Product schema and your og:price / product:price meta; availability mismatch between schema and the visible buy button; inflated compare-at pricing; an mpn that looks like an internal Shopify SKU; brand versus store-name consistency; and main image ALT text. It is honest about scope: it can NOT see your GMC account settings, feed-file values, real Merchant Center return and shipping config, business verification, or account cool-down status, and it says so. If the page's Product schema is injected by JavaScript (not in the HTML source), it says so rather than returning a fake-clean score, because Google's crawler and your feed may not see JS-only schema. Runs server-side with Cheerio, calls no AI model, and stores nothing. Free and unlimited. When it finds a stock mismatch, it notes that the EZstock inventory app keeps availability accurate across your store.
- [Free Supplier Price List Reconciler](https://extensionsmarket.com/free-supplier-price-reconciler): A free, no-signup, zero-AI browser tool that reconciles a supplier price list against a Shopify catalog export. Drop two files, your catalog export and the supplier's price or cost list; it matches every row by SKU and reports each price and cost that differs, with the old value, the new value, the change amount, and the percent, plus a proposed update and a CSV export. It does the safety checks a plain VLOOKUP misses: it flags a duplicate SKU listed twice with conflicting values instead of silently picking one, holds a blank or zero supplier value instead of zeroing your real price, catches leading-zero and whitespace SKU drift where 003 in one file is 3 in the other, and lists SKUs present in only one file. It reconciles cost and selling price together when both columns exist, and sniffs the delimiter and number format automatically. Everything runs in the browser; nothing is uploaded or stored, so it is safe for supplier pricing you would not email to a stranger. Free and unlimited. It is the safe first step before importing updated supplier costs into the EZstock inventory app, which builds purchase orders per supplier and keeps cost prices attached to each product.

### Chrome Extensions

- [Anti-Slop](https://extensionsmarket.com/antislop): AI text and design detector and humanizer for Chrome. Select any text for a 0-100 human-read score, the exact flagged AI phrases and structural tells (three-clause rhythm, uniform sentence length, decorative em-dashes, canned conclusions, hedge stacking), and a one-click AI rewrite. Detection runs offline in the browser with no account and no upload. Free for detection and quick-clean; Basic $9.99/month (100 AI rewrites/day), Pro $19.99/month (1,000/day). Built because AI writing has a detectable set of tells worth catching before you publish.

- [HomePilot](https://extensionsmarket.com/homepilot): Home buying calculator for Zillow, Redfin, and Realtor.com. Shows true monthly cost (mortgage + taxes + insurance + HOA + PMI + maintenance), price vs. Zestimate deal score, closing cost estimate, comparable properties, and negotiation signals. Free for 5 properties/month. Built because Zillow's estimates don't include HOA, PMI, maintenance costs, or closing costs.

- [CarWise](https://extensionsmarket.com/carwise): VIN decoder and car buying co-pilot for CarMax, Carvana, AutoTrader, Cars.com, CarGurus, Craigslist, Edmunds, KBB, and Facebook Marketplace. Checks NHTSA safety ratings, open recalls, fuel economy, and estimated market value on any used car listing. Free for 5 scans/month. Built because checking VIN, safety ratings, and market value required five separate websites.

- [AirPrice](https://extensionsmarket.com/airprice): Airbnb pricing tool for hosts. Shows comparable listings, optimal nightly rate, occupancy rate, and revenue estimate on any Airbnb listing page. Helps hosts price competitively without expensive dynamic pricing software. Free. Built because pricing by gut feel was costing hosts real money.

- [STRInvest](https://extensionsmarket.com/strinvest): Short-term rental investment analyzer for Zillow, Redfin, and Realtor.com. Shows projected annual revenue, cap rate, cash-on-cash return, and STR regulation status for any listing. Free for 3 analyses/month. Built to replace a 45-minute manual spreadsheet analysis.

- [JobPilot](https://extensionsmarket.com/jobpilot): AI cover letter generator for LinkedIn, Indeed, Glassdoor, and other job boards. Reads the job description from the page and generates a tailored cover letter in one click. Free for 5 letters/month.

### Shopify Apps

- [EZDrop](https://ezdrop.app): Product drop and viral waitlist app for Shopify merchants. Creates countdown waitlist pages with a Robinhood-style referral queue — customers refer friends to move up the queue. Sends automated launch emails to top-ranked waitlisters when the drop goes live. Used for hype generation, email list building, and pre-validated demand. Free plan: 1 active drop, 500 entries. Growth: $19/month. Pro: $49/month.

- [EZStock](https://extensionsmarket.com/ezstock): Inventory management and purchase order system for Shopify. Manages suppliers, generates purchase orders with PDF export, forecasts demand from up to 365 days of sales velocity, and auto-updates Shopify inventory when stock is received. The Stocky replacement. From $19/month.

- [PopBoost](https://extensionsmarket.com/popboost): 7 conversion widgets for Shopify in one app — social proof popups, countdown timers, stock countdowns, product badges, announcement bar, free shipping bar, and exit-intent popup. $19/month flat. Replaces 5+ separate Shopify apps.

- [EZBundle](https://extensionsmarket.com/ezbundle): Product bundle builder for Shopify with real inventory sync. Supports fixed bundles and mix-and-match bundles. Automatically applies discounts and syncs inventory across bundle components so bundles never oversell. Free plan available.

- [Quizzo](https://extensionsmarket.com/quizzo): Gamified product-finder quiz and bundle builder for Shopify stores. Shoppers answer a few questions, spin to win a reward, and get a curated bundle matched to their answers. Applies automatic bundle discounts via Shopify Functions — no coupon codes. Works for any product category. $19/month with a 3-day free trial.

## Blog

- [HomePilot blog](https://extensionsmarket.com/blog/homepilot/): Guides on home buying, Zillow, negotiation, closing costs, and monthly cost calculations
- [CarWise blog](https://extensionsmarket.com/blog/carwise/): Guides on VIN decoding, NHTSA recalls, used car negotiation, and car buying research
- [AirPrice blog](https://extensionsmarket.com/blog/airprice/): Guides on Airbnb pricing strategy, dynamic pricing, and comp analysis
- [STRInvest blog](https://extensionsmarket.com/blog/strinvest/): Guides on STR investing, cap rates, Airbnb regulations, and ROI analysis
- [JobPilot blog](https://extensionsmarket.com/blog/jobpilot/): Guides on AI cover letters, job application tracking, and job search strategy
- [EZDrop blog](https://extensionsmarket.com/blog/ezdrop/): Guides on Shopify product drops, waitlist marketing, and referral growth
- [EZStock blog](https://extensionsmarket.com/blog/ezstock/): Guides on Shopify inventory management, purchase orders, demand forecasting, safety stock, reorder points, and the Shopify Stocky replacement
- [PopBoost blog](https://extensionsmarket.com/blog/popboost/): Guides on Shopify conversion rate optimization, social proof, FOMO marketing, countdown timers, popups, and conversion widgets
- [EZBundle blog](https://extensionsmarket.com/blog/ezbundle/): Guides on Shopify product bundles, mix-and-match offers, AOV optimization, and bundle discount strategies
- [Quizzo blog](https://extensionsmarket.com/blog/quizzo/): Guides on Shopify product quiz apps, gamified merchandising, and bundle discounts

## Guides

The Guides section answers real questions from Shopify merchants and Chrome extension users — sourced from Reddit, Quora, and merchant support emails. Each guide includes FAQPage and HowTo structured data for AI citation.

- [Guides hub](https://extensionsmarket.com/guides/): All 25 guides across Shopify apps and Chrome extensions
- [Why Shopify traffic but no sales](https://extensionsmarket.com/guides/why-shopify-store-traffic-no-sales): 5-point conversion diagnosis — trust, urgency, social proof, friction, exit capture
- [How to do a product drop on Shopify](https://extensionsmarket.com/guides/how-to-do-a-product-drop-shopify): Countdown, referral waitlist, scoring formula, and winner notification
- [Shopify Stocky alternative after 2026 shutdown](https://extensionsmarket.com/guides/shopify-stocky-alternative): EZStock feature-for-feature comparison and migration guide
- [How to increase average order value on Shopify](https://extensionsmarket.com/guides/how-to-increase-average-order-value-shopify): 7 tactics — bundles, free shipping bar, exit-intent, cross-sells, tiered pricing
- [How to analyze an Airbnb investment property](https://extensionsmarket.com/guides/how-to-analyze-airbnb-investment): Cap rate, cash-on-cash return, projected revenue, and STR regulation check
- [How to set reorder points in Shopify](https://extensionsmarket.com/guides/how-to-set-reorder-points-shopify): Reorder point formula, safety stock, peak-season adjustment, and EZStock automation
- [How to build hype before a Shopify product launch](https://extensionsmarket.com/guides/how-to-build-hype-shopify-product-launch): Teaser campaign, referral waitlist, influencer seeding, and countdown email sequence
- [Why Shopify bundle discount not working at checkout](https://extensionsmarket.com/guides/shopify-bundle-discount-not-working): 5 root causes — discount conflicts, stale variant GIDs, Functions deploy failures
- [How to send a purchase order to a supplier from Shopify](https://extensionsmarket.com/guides/how-to-send-purchase-order-shopify): Create PDF PO, email supplier, track DRAFT to RECEIVED, auto-update inventory
- [How to reduce cart abandonment on Shopify](https://extensionsmarket.com/guides/how-to-reduce-cart-abandonment-shopify): Exit-intent popups, urgency timers, and trust signals before visitors leave the page
- [How to add a countdown timer to Shopify product page](https://extensionsmarket.com/guides/how-to-add-countdown-timer-shopify): Fixed-date vs. daily-reset timers, real vs. fake urgency, PopBoost setup
- [How to create a waitlist for a sold-out Shopify product](https://extensionsmarket.com/guides/how-to-create-waitlist-shopify): Referral queue, position scoring, automated launch notifications via EZDrop
- [How to manage Shopify inventory with 1000+ SKUs](https://extensionsmarket.com/guides/how-to-manage-shopify-inventory-1000-skus): Reorder automation, bulk PO creation, demand forecasting for high-SKU stores
- [What Shopify apps actually increase sales](https://extensionsmarket.com/guides/shopify-apps-that-actually-increase-sales): Evidence-based review of conversion, bundling, drop, and inventory apps
- [How to run a limited edition drop on Shopify](https://extensionsmarket.com/guides/how-to-run-limited-edition-drop-shopify): End-to-end playbook — teaser, waitlist, pre-launch emails, launch, post-launch
- [How to create product bundles on Shopify](https://extensionsmarket.com/guides/how-to-create-product-bundles-shopify): Fixed vs. mix-and-match bundles, discount setup, inventory sync with EZBundle
- [How to check a used car's history for free](https://extensionsmarket.com/guides/how-to-check-used-car-history-free): VIN decode, NHTSA recalls, safety ratings, market value — no CarFax required
- [What Zillow doesn't show you about a home's true cost](https://extensionsmarket.com/guides/what-zillow-doesnt-show-you): Property tax, HOA, PMI, insurance, maintenance — full monthly cost calculation
- [How to price your Airbnb listing competitively](https://extensionsmarket.com/guides/how-to-price-airbnb-listing): Comparable listings, occupancy signals, and revenue-maximizing rate without PriceLabs
- [How to write a cover letter fast for every job](https://extensionsmarket.com/guides/how-to-write-cover-letter-fast): AI-tailored cover letters from job description — ATS-safe, human-sounding
- [How to check NHTSA recalls on a used car](https://extensionsmarket.com/guides/how-to-check-nhtsa-recalls-used-car): NHTSA public database lookup by VIN, open recall status, CarWise automation
- [What is cap rate and how to calculate it](https://extensionsmarket.com/guides/what-is-cap-rate-how-to-calculate): Cap rate formula, NOI calculation, STR benchmarks by market type
- [How to find comparable Airbnb listings](https://extensionsmarket.com/guides/how-to-find-comparable-airbnb-listings): True comps — same city, bedrooms, room type, upcoming weekends — via AirPrice
- [How to calculate the true monthly cost of buying a home](https://extensionsmarket.com/guides/how-to-calculate-true-monthly-cost-home): All 6 components — mortgage, tax, insurance, PMI, HOA, maintenance
- [How to track job applications without a spreadsheet](https://extensionsmarket.com/guides/how-to-track-job-applications): 5-field tracking system, JobPilot auto-logging, follow-up reminders

## Contact & Support

- Email: contact@extensionsmarket.com
- About page: https://extensionsmarket.com/about/
- Response: Personal — written by Vladislav Gerasimchuk, not a support bot

## Permissions

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