How can we get a in progress transaction that will be done in the future with a callback?

Question

If a client sends a transaction and closes my app, how can my app know the result of that transaction is?

My android application takes the user to Metamask, And the user may close Metamask or both while the transaction dialog is open, and when s/he opens Metamask in the future, s/he will be faced with the pending transaction dialog, and may record the transaction.