Here are a list of apps that I’ve tested out with the Acer Iconia and seem to be optimized for the tablet form factor
Google Maps
Gmail
Contacts
Calendar
Talk
You Tube
Docs To Go
Evernote
Feedly
Pulse News Reader
SwiftKey Tablet X
Thumb Keyboard
IMDB
Due Today
I plan to continually update this page as I find new apps that are interesting.