Mobile App Life Cycle Management

In contrast to web applications that typically run continuously in a browser tab, mobile applications (apps) operate in a far more dynamic and constrained environment. Mobile operating systems like Android and iOS actively manage app execution to preserve battery life, free up memory, and ensure responsive performance. As a result, apps can be paused, suspended, or even terminated without user input, often triggered by incoming calls, low resources, or the user switching apps.

Designing apps without life cycle awareness can lead to serious issues such as lost user data, app crashes, and unresponsive behavior, especially when an app resumes after interruption. Mobile developers must design apps that gracefully handle interruptions, release unused resources, and restore state when needed.

Life cycle overview of mobile apps

Building on the need for life cycle awareness, it’s essential to understand how mobile platforms manage app states differently. Android and iOS have defined life cycle models that dictate how apps move between foreground, background, and terminated states. These transitions are not just theoretical; they directly impact when our code runs, pauses, and what resources must be managed. Ignoring these state changes can lead to inefficient apps that are unresponsive, crash-prone, or abruptly terminated by the OS.

Life cycle of an Android app

On Android, an app’s life cycle is managed through a series of method callbacks that reflect its current visibility and interaction with the user. When an app launches, it enters the foreground through onCreate(), onStart(), and onResume(). If the user navigates away, such as switching apps or receiving a call, the system triggers onPause() and then onStop() as the app moves to the background. If the system needs to reclaim resources or the user explicitly closes the app, onDestroy() is called terminating the app. These transitions allow developers to save state, pause resource-heavy operations, or clean up memory depending on the app’s visibility, and importance.

Life cycle of an iOS app

On iOS, the app life cycle is structured around the following five key states:

• Not Running

• Inactive

• Active

• Background

• Suspended

When an app is launched, it moves from Not Running to Inactive, and then to Active, where it can interact with the user. If the user switches apps or a system interruption occurs, the app transitions to the Background and may enter a Suspended state, during which the app remains in memory but does not execute code. If memory is needed elsewhere, the OS can remove the suspended app from memory entirely. Understanding these states allows iOS developers to manage tasks, save user progress, and ensure seamless resume behavior under various conditions.

We’ve explored how ...