Button Mapper: Remap your keys
Overview
Button Mapper: Remap your keys, developed by Android developer flar2 (Aaron Segaert), is a hardware input interception and automation utility. The application enables users to override and reassign physical buttons, capacitive keys, Android TV remote buttons, and connected Bluetooth peripherals to custom actions, application shortcuts, or complex system macros.
At the operating system level, Android processes physical button inputs through the Linux input subsystem (evdev). Button Mapper intercepts this flow utilizing the Android AccessibilityService API. When registered, the service monitors onKeyEvent callbacks, consumes specified hardware key events, and prevents default system handlers from executing by returning a consumed event state.
Button Mapper establishes a flexible multi-action trigger model for each detected keycode. Hardware inputs can be mapped to three distinct interaction states: Single Press, Double Press, and Long Press. This enables a single physical key (such as Volume Down) to perform its standard audio adjustment on a single press, toggle the camera flashlight on a double press, and trigger a split-screen window mode on a sustained long press.
The application operates without root for standard foreground remaps. However, because Android suspends accessibility event dispatching when the display is powered off to conserve battery and enhance security, standard apps cannot intercept screen-off key events. Button Mapper addresses this via an elevated permissions bridge unlocked through a one-time ADB (Android Debug Bridge) command.
This grant enables the app to bypass standard sleep restrictions, allowing screen-off media track skipping and pocket-detection triggers. For power users, Button Mapper Pro introduces advanced automation tools including broadcast intent dispatching, custom keycode emulation, pocket detection sensors, and rotation-aware volume button inversion.
Pros & Cons
Comprehensive hardware button compatibility across smartphones, tablets, Android TV remotes, and gamepads.
Multi-trigger architecture allowing distinct Single Press, Double Press, and Long Press assignments per key.
Fully operational without root access for all standard foreground device actions and application shortcuts.
One-time ADB command unlocks screen-off track skipping and secure system setting modifications.
Advanced automation suite supporting custom keycodes, broadcast intents, and shell script execution.
Context-aware utilities including pocket-detection suppression and orientation-aware volume button flipping.
- ✕
Screen-off button interception necessitates executing an ADB command via a computer or local terminal.
- ✕
Aggressive OEM power-saving algorithms can occasionally suspend the accessibility service in the background.
- ✕
Cannot remap software-rendered on-screen navigation buttons due to fundamental Android security boundaries.
Download
Get it on Google Play 
Get it on App Store FAQs
How does Button Mapper intercept physical hardware keys without root permissions?
The application utilizes the Android Accessibility API (AccessibilityService), which grants permission to monitor onKeyEvent input streams and remap them to new system actions.
Why is an ADB command required to remap buttons while the screen is turned off?
Android disables standard accessibility key monitoring when the screen is asleep. The ADB command grants WRITE_SECURE_SETTINGS, allowing the app to maintain low-level input hooks in sleep states.
Can Button Mapper remap OEM-specific buttons like Samsung’s Bixby or Google Assistant keys?
Yes. The application successfully intercepts dedicated assistant hardware buttons on most devices, redirecting them to user-selected apps or functions.
How can users prevent Android from disabling the Button Mapper accessibility service?
Users should navigate to System Settings > Battery Optimization and set Button Mapper to "Unrestricted" / "Don't Optimize" to prevent background task termination.
Does Button Mapper work for remapping Android TV and Google TV remote buttons?
Yes. When installed on Android TV / Google TV, it can remap dedicated remote buttons (such as sponsored streaming keys) to open preferred media apps.
Hot Reviews
Summarized from Google Play reviews and community discussions.
Users frequently highlight how Button Mapper rescued devices with broken power or volume buttons by reassigning their functions to alternate hardware keys.
Television power users commend the application for effortlessly remapping unused sponsored streaming buttons on Google TV remotes to home media servers.
Technical reviewers praise the balance of offering standard no-root accessibility remapping while providing an ADB pathway for advanced screen-off media control.
Some users on aggressively managed Android skins note that the accessibility service occasionally requires manual toggling after system reboots.