Samsung's default file manager is very good actually, except that it can't put shortcuts on the homescreen.
The first thing you could do to see what kind of apps you may want to put into your phone is to just go to the Play Store and look at the apps "recommended for you".
__________________
------------------------------
SugarSync and DropBox Referrals
SugarSync (gives 5gb free on registration)
DropBox (gives 2gb free on registration)
|