Pou

Pou is a small brown alien blob, and looking after one turns out to be a long-term commitment. Zakeh's virtual pet asks the classic Tamagotchi questions — is it fed, is it clean, is it entertained, is it asleep — and answers them with a creature that grows up as you care for it. It sounds simple. It is. That is why, over a billion downloads later, people still have a Pou.

The daily routine is the game: meals in the kitchen, washing off the dirt, putting Pou to bed, and keeping its mood up. Care earns experience, levels unlock new content, and the Game Room's mini-games pay out the coins that fund everything else. In the Lab, potions experiment on your poor pet, growing it, shrinking it, and changing its colours — science in Pou's world has loose ethics and funny results.

Customisation is where the coins go. Outfits, hats, and eyeglasses dress Pou up; wallpapers redecorate each room of its house; achievements and special items give collectors targets to chase. You can visit friends' Pous and play with them, and talking to Pou gets your words played back at you in its own squeaky voice — a small joke that never quite gets old.

It is a gentle, low-pressure game that fits into spare minutes: feed, wash, play a mini-game, done. Children love the silliness, and older players often keep it out of pure nostalgia. Either way, Pou remains the virtual pet to beat on Android, mostly by refusing to be anything more complicated than a pet.