Will an app you install today still work in ten years?

Local software is not automatically durable

Running locally avoids some remote-service dependencies, but compatibility and maintenance still matter. Apps depend on operating-system interfaces, signing arrangements, and processor architectures that can change over time. Requirements and migration paths vary by platform; local execution does not guarantee long-term operation.

A local app may keep working through many updates and then encounter a compatibility change. The cause could be a retired interface, signing requirement, processor architecture, or another platform change. Outcomes depend on the app and platform, and maintained software may have an update path that abandoned software lacks.

The same dependency behaves differently on a one-year clock and a ten-year one

Servers, accounts, certificates, and platform interfaces can change on different schedules. Long-lived software may need service replacements, renewed signing credentials, and updates for newer platform versions. The actual requirements depend on the platform, service, and deployment model.

Platform changes may be announced and include migration periods, but timing and compatibility support vary. Maintained software can sometimes be updated; abandoned software may have no compatible version when an interface or processor architecture is retired.

What a program has to avoid depending on

Durability is mostly a subtraction problem. Every outside thing a program needs is a thing that can be taken away, and each one has an owner who is not you. The shortest useful test is to ask what the app would do if the phone never touched a network again.

• A server. Anything fetched at launch, whether a license check, a configuration file or the actual computation, is a dependency with an owner and a budget.
• An account. A login is a server dependency wearing different clothes.
• Undocumented interfaces. The public ones everybody uses are the last a platform will break, because breaking them breaks everybody.
• A certificate that has to be renewed by a company still in business.
• A separately installed runtime or framework the operating system is free to remove.
• A file format only that one app can read. Data in an opaque container dies with its reader.

So what are the real odds?

No honest answer here is a flat yes. The best odds belong to a program that does its work on the device, uses public and widely used system interfaces rather than undocumented ones, writes its data in a format other software can read, and still has source code somewhere so it can be rebuilt against a newer system. That is a real chance, not a guarantee.

Hardware has its own decade, and batteries and storage wear out on a schedule of their own. Staying on an old system version buys stability and costs security fixes, which is a genuine trade rather than a loophole. A tool can reduce outside dependencies, but it still lives within the limits and maintenance cycles of its hardware and software.