It was built by Consen Labs. And presently it is world number one largest ethereum digital asset wallet. It store major share of the already mined ethereum, and it is a multicurrency wallet in that it support almost all erc20 tokens as well as some coins and the tokens built upon them.
The wallet goes beyond holding coins alone, there is opportunity to swap tokens with the in-built exchange and there are dapp games with which the user can play like Hyperdragon, Decentralads, Coinswita etc. One can also stake some coins in it as well, like Loom and Atom. There is also inbuilt DeFi program where one can lend its coins and earn some interest.
The security of your wallet to some extent is in your hands also, because the company does not store your private key instead it is stored at your level and you have to back it up with the seed phrase which must be kept securely.
The wallet has good support service in that when having an issue the team is easily accessed.
So when thinking of the way to store your ethereum and some other coin and also enjoy additional services, imToken might be your answer.