I mean, it would be nice, for the sake of all the people growing up today, if you took something like 'Total Recall' at 5:00 minutes and had them explicitly and robotically ask each other for consent. I think that would do a whole lot more good than having your tinder fling download a 20 gb blockchain onto their cellphone before the date. (Sorry to slightly make fun of this - I think the idea is good actually, and haven't played with it enough, but just wanted to make a point in this direction).
To address this app specifically though- wouldn't such an app not really matter in the direction of: you can always say 'no' during the course, and then the required behavior is to stop. I'm not sure if that would be reflected very well in the app, since the person could point to the consent and say it was given, when in fact, it may have initially been given, but the more important point was that it was (maybe the word is ) rescinded .