Our friend Nancy Jo swears by the free 7 minute app. She says it totally gets you winded, and come on, it's only seven minutes. I'll report back next week in the comments section. And if you have any other suggestions, I'm all ears.
Tinybop is a tumblr-like collection of apps, sites, and books for design fan parents! I particularly like how many apps they include—the iTunes store is useless for this type of curation.