He can tell it to you or publish it in his store on a sign. He'll also be in your contacts and transaction history after you've had at least one transaction and then you can just click his name/avatar.

asoltys

How would I find Bob's profile username though?

earnbitcoin

Yeah still debating whether to keep it this way or not. I had a "Done" button for a while but came up with this as a way of keeping the success screen nice and clean.

After I hit send, there's no buttons anywhere.  I understand now that I can just click anywhere and it will return to a view that has button.  But it seems odd to not have an [OK button], or [Continue] or [Next] or something like that.