How much does it cost to maintain an app? The fees, the forced updates and the labour

Apple Developer Program: 99 USD per membership year. Required to stay on the App Store.

Google Play: 25 USD once. There is no yearly fee, but Google closes inactive accounts, below.

Backend. Hosting, database, file storage and sign-in. Firebase, Supabase and similar services price by usage, so the cost grows with your users. Check each provider’s current pricing page for your expected usage.

Paid services inside the app. Maps, AI model calls, email, analytics, subscription management. Each has its own plan.

Your build tools. If you maintain the app with an AI agent, your AI subscription and the tool’s plan. Modaal has no credits: the AI runs on your own subscription, and Pro is €9 per user per month billed annually.

Labour. The hours spent on updates, fixes and features, by you, a freelancer or an agency. This is the line that varies most between apps.

Apple: the minimum SDK. Since 28 April 2026: “Apps uploaded to App Store Connect must be built with Xcode 26 or later using an SDK for iOS 26, iPadOS 26, tvOS 26, visionOS 26, or watchOS 26.” Apple publishes each new minimum on its Upcoming requirements page. Any update you upload, even a one-line bug fix, has to meet it, so an app that has not been rebuilt for a year needs that work first.

Google Play: the target API level. Since 31 August 2026: “New apps and app updates must target Android 16 (API level 36) or higher to be submitted to Google Play.” And for apps you do not update: “Existing apps must target Android 15 (API level 35) or higher to remain available to new users on devices running Android OS higher than your app's target API level”. Google allows an extension to 1 November 2026 on request.

Store questionnaires. Apple asked every developer to answer updated age rating questions by 31 January 2026 “to avoid an interruption when submitting your app updates”. Apple also says of the privacy details on your listing: “You're responsible for keeping your responses accurate and up to date.” Adding an analytics or advertising SDK means updating them.

On the App Store. If the membership lapses: “If your Apple Developer Program membership expires, your apps will no longer be available for download and you won't be able to submit new apps or updates”. People who already installed the app can keep using it.

Apple also reviews old apps. Developers of apps “that have not been updated within the last three years and fail to meet a minimal download threshold” get an email, and “You'll be asked to submit an update within 90 days to keep your app on the App Store.” And: “apps that crash on launch will be removed immediately.”

On Google Play. An app whose target API level falls behind stops being available to new users on newer Android versions. Google also closes inactive developer accounts: for example, an account over a year old whose apps have “less than 1,000 combined lifetime installs”, whose contact details are not verified and which “has not used Play Console in the last 180 days.” Google sends reminders “with 60, 30, and 7 days notice.”

In the code. The longer an app goes without updates, the larger the first update becomes: a new SDK, new library versions and new OS behaviour all at once.

The fees above are the same for every app. The hours are not. Two apps with the same features can need very different amounts of work for the same change.

Changes stay local. In a well-structured app, a change to the profile screen touches the profile code only. In a tangled one, it breaks the chat. Each fix then needs another fix.

Tests catch what broke. Automated tests run on every change and show what stopped working before users do.

Decisions are written down. A spec per feature says what the feature is meant to do. The next developer, or the next AI agent session, reads it instead of guessing from the code.

The code is yours and standard. A standard Xcode or Android Studio project in your own Git repository can be maintained by anyone you hire. Code locked inside a builder you have left cannot. Code export vs no-code lock-in lists what you can lose.

Two platforms, one set of decisions. Two apps maintained separately need every change made twice and checked twice.

When these are missing, each new feature can break an old one, and owners end up rebuilding the app from scratch, which costs more than any update.

An agency retainer. A monthly fee for an agreed number of hours or an agreed response time. Suits a company that wants the app looked after without managing it.

A freelancer by the hour. Cheaper per hour, but check availability: the person who built the app may not be free when Apple’s deadline arrives. How to hire an iPhone app developer covers handover and support periods.

Yourself with an AI agent. The agent makes the SDK update, the fix or the feature; you review it, test it on a phone and publish it. In Modaal each feature has a spec and a plan, the code is a standard Xcode and Android Studio project in Git that you can export at any time, and the shared feature logic is checked by tests on both platforms, so one change is made once for iPhone and Android.