-Google Drive / Box / Dropbox, for teh cloud keeping,
-Google Keep, notes / Life planning, can be accessed from any device
-MX player, video player that supports just about any format out there
-Microsoft Office
-TrackID, the best music recognition app, keeps history of the tracks, can be accessed from any device
-Smart connect, triggering tasks by connecting an accessory.
-Playstation app, if you have a PS4
-Playto / twonkybeam, stream media and Youtube to your tv through DLNA device
-Snapseed, great picture editor