12 tools. One developer.
Built to actually work.
Extensions Market is a one-person indie studio out of San Francisco. Every product started as a problem I ran into personally — a spreadsheet that should have been a button, a calculation that should have been instant, a workflow that no existing tool handled well. So I built it.
The story
I started with a simple rule: only build something if I would use it myself.
AirPrice came first. I had an Airbnb listing and was pricing it by gut feel — occasionally checking nearby listings, making rough mental comparisons. A bad way to price anything. I wanted a tool that pulled comparable listings, computed an optimal rate, and surfaced it right inside Airbnb. No one had built it. So I did.
Then STRInvest. I was analyzing whether a property was worth buying as a short-term rental. Every time, it was 45 minutes in a spreadsheet — cap rate, projected occupancy, cash-on-cash return, STR regulations. I built an extension that does it in under 60 seconds, right on the Zillow or Redfin listing page.
HomePilot came from buying my own house and realizing that Zillow's estimates tell you nothing about what you'd actually pay each month — no HOA, no PMI, no maintenance, no closing costs. CarWise came from buying a used car and wishing VIN lookup, safety ratings, and real market value were all in one place instead of five separate websites. JobPilot came from watching friends rewrite the same cover letter a hundred times for jobs that deserved a tailored response. Anti-Slop came from reading a wave of AI-written copy and AI-generated pages and wanting a fast, honest read on what was machine-made.
The Shopify side followed the same logic. EZstock exists because Shopify retired Stocky, their own inventory tool, leaving thousands of merchants without a solution. EZDrop exists because product drops deserved a viral waitlist mechanic that builds word-of-mouth before launch day. PopBoost exists because conversion widgets shouldn't require five separate app subscriptions. EZBundle exists because bundle apps that don't sync real inventory are a liability. Quizzo exists because any store deserved a gamified, quiz-powered bundle experience — spin to win, curated recommendations, and a discount that applies itself at checkout. Marjn exists because Shopify shows you revenue, not what you actually keep — so it answers true-margin questions right inside Sidekick.
None of these came from market research or trend-chasing. They came from real friction — mine, or a merchant's, or a user's. That's the only filter that matters.
The products
What I believe about software
Questions or feedback?
I read every email and respond personally — no support bots, no ticketing systems, no waiting.
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