I don't think that's always the case. If you're going to straight up tell someone to install it, you might as well tell them directly that you're out. The app is for people who secretly would rather not go but still would honor the agreement. If both people use the app, it discreetly forms a new agreement. I would consider this app but would never flake on plans. If something were to happen to prevent an event then great but otherwise I still go. You could still drop hints to install the app like "haha look at this crazy app" and leave it at that. Anyway, I just woke up so hopefully that made sense.