ever since i got the ipad, my iphone is getting no love.
it's jailbroken, so most of my must haves are not in app store.
as far as app store apps:
reeder - this i use the most. for reading rss feeds.
all of the above, except for sbux card, have much better ipad versions though.
another amazing one is pulse: volume one for ipad. can't stop playing it