Breadwallet is a good wallet for iPhone; With Apple there is nothing to choose from. On Android, developers claim that Breadwallet is superior as it only runs on Marshmallow + and uses secure hardware storage for private keys. I am using it and its syncing is slow and it sees charges erroneous on the higher side; There is no option to change it manually. The best wallets for Android are Electrum, Mycelium, and Samourai. and I think the bread wallet is best for you if you have a Phone. It is the most secure wallet and makes it even more secure than before with IoS security on iphone.