Slither.io has a mobile version which is available on iOS and Android for free.
Artificial Intelligence Edit
The Artificial Intelligence is an offline game mode where you can play Slither.io Mobile version with bots. Bots don't usually go and kill you. When you go for traps on bots, they don't run away from your trap and try and kill you so it's easy for you to trap them. If you kill a bot, then it won't show all red dots. When any skin dies of their used skin, it will correspond their colour - it would all be rainbow. Also, when you boost, it would even show rainbow pellets.
Slither.io Mobile Skin Gallery Edit