Sorry about the vase

Three questions, and it drafts you a card that actually apologises. Then it shows you the message most people send instead, and marks the parts that undo it.

1Name the thing you did.
2Say what it cost them.
3Offer something specific.

Then stop. No "if you felt". No "but" — everything before a "but" is cancelled by everything after it. And no asking to be forgiven, which is one more thing you want from someone you have already taken from.

Nothing is stored or sent. The card is worked out here, from your three answers, and then it is gone.