I'm running out of room on my iPhone for apps, but developers don't seem to care about my particular limitations. They keep churning out political apps, and some of them are quite good. A few campaigns are experimenting with apps, but I've yet to see one that really involves the medium. Let me know if I've missed anything. (My first list can be found here.)
1. Meet The Press (free), featuring clips from the show, tweets from Meet producers, a way to send e-mails directly to host David Gregory, and more.
2. C-SPAN Radio (free) -- get CSPAN 1, CSPAN 2 and CSPAN 3 whenever you want, provided you've got a connection.
3. iPolitics ($0.99) -- it's a fairly simple app that collects and curates political stories from newspapers and bloggers. Compare with asap-Politics, which also costs $0.99 but has a better interface.
4-7. New apps from Slate, Newser, Politico and Huffington Post. (You can find them on your own.)
8. The Atlantic's two apps: one of which is being rebuilt, and the other, Atlantic Wire, brings you the best aggregation in the business.
9,10. Congress and Congress+ -- one's $0.99, the other costs $4.99 -- an indispensable guide to members of Congress, their races, their legislation and news about them. Also handy: accurate e-mails for key staffers.