Money on a phone — spec it like the network will fail mid-transfer

A field app that loses a photo is annoying. A money app that loses — or duplicates — a transfer is a loss, a support case, and sometimes a regulator. Everything in the generic mobile contract still applies (offline queue, idempotency, permissions); this pack is the part that is different because it is money, and it is the part community skill sets do not carry, because it is domain knowledge rather than framework knowledge.

The through-line: the phone is not the ledger. It is a client with an opinion, and every screen must be honest about how strong that opinion is.

1. A balance has three states, never two

confirmed · pending · unknown. A number rendered without which of the three it is, is a lie the user will act on.