Nyano is a meme about the famous Nyan Cat and the glorious cryptocurrency Nano.
Web & mobile wallets were created to show 1 nyano = 10^-6 XNO (Nano's canonical denomination) to let people play with the feeless digital currency in small amounts, but are now abandoned. You can find the original codebase and some useful references here.
You can still use the Nano payment network, which is stronger than ever, just by adding some zeros after the decimal separator 😊
Refer to nano.org to find the currently supported wallets as well as exchanges allowing you to swap it from your local traditional currency.