Can the list include games? Because if so, all five would be Kairosoft games.
If not:
- Waze (recent find, very helpful, esp if you're not in a country where Google maps is completely updated. Takes traffic information uploaded by users to map the fastest route. Has saved me hours so far)
- WhatsApp (not because I like the way it works, but more that it's become a commonly accepted app so I have to use it)
- Titanium Backup (this baby and I go way back. I keep her around because I know that no matter what happens, she's got my backup)
- Reddit is fun (because reddit is fun)
- SwiftKeyX (by far the best keyboard out there, can't believe I didn't think of this one first. Very critical)