http://t.me/twa_moneybox_bot/app
(source: https://github.com/paprikashio/moneybox_twa/commit/1ace2cf65bfe05334a8fbdaf7403d3e0cf43ae79)

The application will help you save money and not use it earlier than planned. The user specifies the savings goal, amount and deadline date. The piggy bank is deposit with TON coins. The smart contract blocks the withdrawal of money before the deadline.