us 1: I can log in with my facebook account.
us 2: I can create a transaction and wait for another bro to confirm it, after a transaction is confirmed, it is public.
us 3: I can see notifications on transaction confirmation request, I can only accept it or leave it be.
us 4: I can delete my unconfirmed transactions.
us 5: I can calculate my debt/loan with another bro.
us 6: I can flush (pay all my debt) to another bro by pressing one button.
us 7: I can see all current transactions.
us 8: I can filter transactions by date, bro, status
us 9: I can see all unconfirmed transaction in one page.