Pou is a virtual pet app that became inexplicably enormous, particularly among children in the early 2010s. Your pet is a brown blob with three eyelashes and no discernible species, and you feed it, clean it, and play mini-games to earn coins for hats.

It sits in a long tradition running from Tamagotchi onwards, and the appeal is the same: something that needs you at regular intervals. Pou's version is unusually forgiving - he gets unhappy but he doesn't die, which is arguably a kinder design decision for the audience.

The mini-games are simple and the mini-game currency loop is genuinely well tuned. There's always a hat or a wallpaper just slightly out of reach.

The design is what made it spread. A brown lump is easy to draw, easy to recognise, and generated an enormous amount of playground-level fan art.

This collection covers Pou and his accessories.