These examples are ready made android classes to be used in codecamp projects(or anywhere). Remember to check AndroidManifest.xml , layouts folder , values folder and classes.
Gui elements howto
Simple multiple views in one activity example(also using random,changing text,text size,text colour of buttons, system time)
Multiple Activities
File handling example
Example of playing media( and closing Activity, loading file list of directory's files, buttons, togglebutton …)
Record Audio
GPS location example and discussion in stackoverflow.com
Accelerometer
Fetching data from Internet.(Notice permission need to be set to allow this and fetching data should happen in separate thread)
Snake game example using acceleration to control
Googles examples
Random ones: