It’s a Tamagotchi… on a mobile. My mobile, in fact.

It being on a mobile means two things:

1) It can’t call out and annoy you, you have to load the game to check how the little guy’s doing.

2) It can look a bit nicer than a low-res LCD display.

Other than that, well, it’s a Tamagotchi. More advanced than the original ones, less advanced that the current ones.