Features - arthurbenemann/ardupilot GitHub Wiki

It's easy to add new features and functions to APM, thanks to the open source code, easy-to-use Arduino IDE and modular nature of APM. Many users have contributed code that adds features that they have found useful. The most popular ones eventually get integrated into the main code, but you can use the others simply by adding the code to your APM folder and compiling and loading via Arduino (rather than the Mission Planner).

Please note that this page is maintained by the users who contributed the code, not the APM dev team. So use at your own risk and contact the author(s) of the code for questions, not the dev team.