what app

Write markdown in any app.

Access Terminal.app with a keystroke.

System maintenance app; performs many useful tasks.

Flash card app for studying and memorization.

CU-SeeMe video conferencing app.

Color picker app that combines color conversion and Retina image reduction.

Drawing app, capabilities similar to Illustrator/Freehand/CorelDraw.

Music notation app.

Bitcoin and Litcoin mining app.

Graphing and data analysis app.