A mobile application is not a deliverable you receive and own in a finished state. It is a product that lives inside two platforms you do not control, both of which change on their own schedule. Budgeting for the build alone is the most common reason apps are quietly abandoned twelve to eighteen months after launch.
What changes without you
- iOS and Android release major versions annually, and each can alter behaviour your app relies on.
- App stores raise their minimum SDK requirements; falling behind eventually blocks updates entirely.
- Store policy changes — privacy declarations, data disclosure, account deletion — apply to existing apps, not only new ones.
- Libraries you depend on publish security advisories that require patching.
- Devices with new screen dimensions arrive and expose layout assumptions.
What a maintenance plan should cover
- Compatibility updates for each major OS release, tested before the release reaches users.
- Dependency and security patching on a defined cycle, with urgent advisories handled immediately.
- Crash and error monitoring, with someone accountable for reviewing what it reports.
- Store compliance work as policies change.
- A modest allowance for the improvements real usage always reveals.
Decisions that reduce the ongoing cost
Maintenance cost is largely determined during the build. Fewer third-party dependencies means fewer advisories to chase. A single cross-platform codebase means compatibility work is done once rather than twice. Automated tests around the critical paths make an OS upgrade a verification exercise rather than a full manual regression. None of these choices are free, but each one is cheaper than the maintenance it prevents.