extensions

App Inventor Extension components can be used in building projects, just like other components. The difference is that extension components can be distributed on the Web and loaded into App Inventor dynamically: they do not have to be built into the App Inventor system, and they can be imported into projects as needed.

KitchenSink -- Adhoc / utility extension
KeepScreenOn - Can be used to keep screen on and prevent it from going to sleep
IsNetworkAvailable - Checks to see if network is available or not; i.e. is device connected to network
SortList - Sorts a list in ascending or descending order

LightSensor - LightSensor used to measure the ambient light level (illumination) in lx
Currently requires a Android Permission which prevents it from building .apk properly
A request will be put to MIT for adding the permission