Taking pictures or videos using a third-party app is fairly straightforward, using ACTIONIMAGECAPTURE or ACTIONVIDEOCAPTURE. However, you as the developer have little control over what happens with the image or video, other than indicating where the result gets stored.
It is an experimental project for switching day/night mode on Andorid.
This is a tiny library which empowers TextView's compound drawables with size specifying and vector support.
This is just an extension of Android's