I think that Xapo is the best online wallet there is for the payments without any fee's these days, I think that these wallets without any fee's are mostly bad secured.
I agree and highly recommend Xapo. I'm using it over a month now and never had any issues. And it's not just wallet, they offer other services like vault and their debit card. I have it and it makes using Bitcoin much more easy and convenient. You should try it.