snap a receipt

photograph the paper. Nothing is typed and nothing is logged into — the bank line it belongs to is chosen later, at the desk.
already have the file?
no login and no tunnel — this page can post a receipt and do nothing else. It waits in the books inbox until somebody files it against a bank line.

put this page on the home screen and it opens in one tap: iPhone — Share, then Add to Home Screen. Android — the ⋮ menu, then Add to Home screen.