A personal assistant, built and run by one person, for that same person.
Ada is reached over Telegram and answers in Spanish. It captures money movements from text and voice notes, keeps track of what is still pending, manages its owner's Google Calendar, and reads his Gmail so it can answer questions about it.
There is one user: the developer. Ada is not offered as a product, has no sign up, and nobody else can talk to it — the bot ignores every Telegram account except its owner's. The source code is kept in a private repository.