Coinomi is good but it doesn't have all the altcoins that atleast passed their ICO's and go further with the roadmap.Some are missing from it.Maybe a wallet that will add all the main coins(BTC,ETH,etc) and altcoins(that finish their ICO) and will generate a new address for each wallet of the respective coin.Something like a masterwallet that will contain all of them and with a windows/mac/linux,etc versions.Maybe it sounds stupid or it really is.That's just an idea.
Coinomi doesn't have a desktop wallet I think. I prefer doing all my stuff on a computer.