changemonitor.io

Website monitoring. Native iOS and Android, Python backend, built on open source.

Specification

PLATFORMS: Native iOS in Swift and SwiftUI, native Android in Kotlin and Jetpack Compose, both built by me
BACKEND: Python. Fetching pages, diffing and alerting all run server-side.
FOUNDATION: changedetection.io, open source I contribute code back upstream.
STORE: Live in the App Store and Google Play. From first concept to release, by me.

changemonitor.io is my own product, not a demo. It runs native on iOS and Android, with a Python backend that fetches pages, diffs them and alerts you, all on top of the open-source changedetection.io. That is the proof: I find my way in someone else's codebase and build a product on it that keeps running.

See changemonitor.io

The app, or the developer?

You want to watch pages: prices, stock, job listings, terms: PickThe app; Whychangemonitor.io is built for exactly that and is live in both stores.
You already run changedetection.io and want it on your phone: PickThe app; WhyThe app is a clean, native client for the open-source changedetection.io.
You are judging whether I get productive in an unfamiliar codebase: PickThe developer The pointThis is why it is on this site.; WhyI built a working product on someone else's codebase and contribute my changes back to that project.
You want iOS, Android and the backend from one pair of hands: PickThe developer; WhySwift with SwiftUI, Kotlin with Jetpack Compose and the Python backend, all three by me.
You want one cross-platform codebase, Flutter or React Native: PickA different developer; WhyI build native on both platforms. That is a choice, not a compromise.

Proof, not a promise

Live in the App Store: Detailchangemonitor for iOS, publicly downloadable; Source: App Store
Live on Google Play: Detailcom.robmulder.changemonitor, native Android; Source: Google Play
Built on top of open source: Detailchangedetection.io on GitHub. I contribute code back to the project.; Source: GitHub
The product runs in public: DetailOpen to look at and use, not just a case study on this site; Source: changemonitor.io
Not the only unfamiliar codebase: DetailMerged work in Signal-iOS, lottie-ios and firefox-ios, listed with links on the homepage; Source: Open source

Read on

Available now.

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Sheet revised 2026-09-29. Every figure on this page can be checked through the sources above.