Most softwallet (those that sync very fast) is centralized. I dont mind it being centralized as long as the developers is people that I can trust. I'd say the best Android wallet (at least for me) is Mycelium. Been using it for more than a year and have never encounter any major problem - only problem is that the speed is a little bit slow.
Well If we take Electrum for example , It's sync very fast (Lightweight wallet) however It connect to servers but .. in the same time they don't have access to our private keys .
So I want something similar without the need of downloading the blockchain . Bitcoin wallet (for android the one based on Bitcoin Core) need to download the blockchain ? I guess not ? I don't see how it will download 50gb in a phone .. :/