Apps

 Just a few quick notes about some apps that I find useful for music-making:

1. Clockwork is a great metronome app that has a snazzy interface and lots of cool features. Well worth $0.99!
2. Even though my trombone was tuned at the factory, Cleartune ($3.99) keeps me honest when it comes to using the alternate slide positions that are so often required for fast passages. That, and I really dig the sound of Pythagorean Just intonation set at A4 = 443.7 Hz. Seriously, I never knew pitch inflation was such a big problem.
3. The Amazing Slow Downer is a little pricier at $14.99 for the full version, but if you're into playing along with Aebersold workbooks and other recordings, it's well worth it. It can speed things up and transpose, too!
4. It's not specifically music related, but Lift is an app that helps establish and maintain habits. 

What apps do you use for music-related stuff? Put it in the comments!

Update: I just found Time Guru, which gives you the sadistic option of selecting a percentage of the beats that the app randomly remains silent on. You can slowly ramp up to this amount, or have it start right away. Pure mayhem genius! As an added bonus, some of the available tones are synthesized voices speaking "one, two three, four", etc. in a few different languages.