Collaboration Apps

Here is my attempt at comparing a few apps for group work.  Do you have others you would like to try?

App Name	Price	Show Files?	Share on Web	Share on App	Share w/ computer	Notes
SyncPad SyncPad Reader	$10 host; $0 guest	PDF from Dropbox	Yes	Yes	Yes – in web browser, read only	Really needs a strong wifi signal to work well; Only host apps can edit, but they can edit at the same time
Share Board Share Board Client	$8 host; $0 guest	Images from Photo Library	No	Yes	No	Only shares across 4 devices at a time; works on iPad or iPod Touch
Sundry Notes Pro; Sundry Notes	$3 $0 w/ ads	PDF from Dropbox, Evernote, Google	No	Yes	No…? But does have Facebook / Twitter integration?	Seems to have a LOT of features, but the interface is not easy to figure out
Air Sketch	$8 $0 guest	PDF from other other apps	Yes	Yes	Yes, in web browser on same wifi	Sometimes loses connection