Quoted By:
Right, I should probably explain for those out of the loop.
The Eevee Tama is a variant of the Tamagotchi Nano, which originally came out in 2010. It has no icons; you check what it needs by pressing the C (far right) button, and open the menu to care for it with the A (far left) button. They eat, play games, poop, and can get sick or depressed. They're made to be quick and easy virtual pets. There were two versions of the original with different characters between them.
Bandai made two licensed versions in 2017. The first was the Pocket Usatama, exclusive to Tokyo Disney and featuring Disney's new Easter mascot. It was identical except the poop function was replaced by the Usatama sometimes attempting to run away.
The second one was the Gudetama Tamagotchi, based on the Sanrio character. This one has a slightly larger screen than the previous three, which the Eevee Tama is getting. The Gudetama is unique because it has 20 possible death screens, and the objective is to see all of them. This is the only Nano that made it to the US so far.