Open an app’s page, or User settings › My account, and choose Add to my account. The screen lists what the app may do, what it sees — who ran a command, what was typed after its name and where, and what you type into a form it opens or which of its buttons you press — and what it never sees: the conversation’s messages and who is in it. Remove it there at any time and it stops at once.
Its commands appear in the / list of your direct messages and group conversations, and in communities whose stewards turn on Apps from people’s accounts in Apps & agents — off until they do. An answer is posted as your message, shown “with” the app, for everybody there to see, or shown to you alone; it names nobody and cannot be edited, and a notification of it or a forwarded copy still says it was said with the app.
They are not used where somebody in the conversation has blocked or ignores you, where you are a guest, or in a channel shared with another organization, and a community’s command rules hold for them. Your settings keep your own record of adding, removing and using them for 90 days. Kemble Work keeps the apps its workspace adds.