Some other good apps you might find useful:
ES File Explorer
- there are other better looking ones but I found this to be the most functional
Evernote, Google Keep
- Good note taking apps. Catch used to be my favorite, but unfortunately they shut down their services. If you're looking for an offline service, SomNotes might be a better alternative.
- Great Reddit client
All google apps like Drive, Gmail, Google+, Maps, and Youtube
- Much better than the default gallery app
- Far better than Samsung's shitty UI
- Great little app for pushing content to your phone from PC
- File transfer using WiFi
- If you're rooted, get this app.