AppGapFinder

About AppGapFinder

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AppGapFinder is a free, no-login web tool for App Store competitor analysis, built and maintained by one person: Linas, an independent iOS developer. This page covers who is behind it, why it exists, how it is built, where its data comes from and how to get in touch.

Who builds it

AppGapFinder is made by Linas, an independent iOS developer who publishes at linasdev.io, on GitHub as linas404 and on X as @linasdev404. There is no company or team behind the tool: every part of it, from the Apple data fetchers to this page, is written and maintained by one developer.

Linas builds iOS apps. More about that work, and anything else worth knowing about the person behind AppGapFinder, lives on linasdev.io.

Why it exists

Paid ASO suites model downloads and revenue, track rankings over time and cover Google Play. They are built for ongoing monitoring, and they are priced for it. The question at the start of a new app is simpler: who already ranks for this keyword, what do they charge, what do their screenshots promise, and what do their users complain about? AppGapFinder exists to make that first competitor-research step quick and free, one keyword at a time, without an account.

How it is built

Public App Store data only
Keyword results come from Apple’s public App Store search, which returns the top 50 apps for a term in any of 49 storefronts. Metadata, screenshots, prices and in-app purchase tiers come from Apple’s public listing data, and reviews from Apple’s public review feeds, covering 18 countries plus the storefront you searched. All of it is data anyone can read without logging in; nothing is scraped from behind a login.
Your data stays in your browser
There are no accounts, no sign-up and no payment. Keywords, fetched app lists and AI settings are kept in your browser’s local storage; collected reviews are cached in IndexedDB for seven days. There is no sync and no server-side profile, so another browser starts empty. The privacy page lists exactly what lives where and for how long.
Bring your own AI key
The optional gap analysis runs on OpenAI, Anthropic Claude or Google Gemini with an API key you supply. The key is stored in your browser, in plain local storage or encrypted with AES-GCM behind a passphrase, and is forwarded to the provider only for the run you start. It is never written to a database or a log. The prompt treats review text as untrusted data and asks for concrete, evidence-backed output rather than a general summary.
A small web stack
The site and the workspace are one Next.js and React application written in TypeScript, styled with Tailwind CSS and hosted on Netlify. Serverless functions proxy requests to Apple and run AI jobs in the background, and public responses are cached on the CDN so a popular keyword or app does not hit Apple again for every visitor. Pages ship with a strict, hash-based Content Security Policy, and rate limits protect Apple and the AI providers from abuse.
What it deliberately leaves out
No download or revenue estimates, no keyword rank tracking over time and no Google Play. It is a qualitative read of one keyword’s competitive set, not a monitoring suite.

Get in touch

Bug reports, questions and suggestions are welcome. The quickest routes are:

Questions about data handling are answered on the privacy page. If something there is unclear or wrong, say so and it will be fixed. If AppGapFinder helped you ship something, or you found a keyword where it got the picture wrong, that is worth hearing too.

App Store is a trademark of Apple Inc. AppGapFinder is an independent tool and is not affiliated with or endorsed by Apple. Back to the home page or open the tool.