With respect to the idea of consent via app - it's simply a dumb idea. People can change their mind, use of the app can be forced, then there's the whole tracking and data privacy issues (the slut-shaming potential of this data can't be overstated, especially in a courtroom context. "But your record shows you consented to 5 other sexual liasons in the last 3 days").
Consent is given continually and can be withdrawn instantly. If in doubt whether you have consent, then you probably don't. So ask (again) or stop.
https://www.theage.com.au/search?text=consent
With respect to the idea of consent via app - it's simply a dumb idea. People can change their mind, use of the app can be forced, then there's the whole tracking and data privacy issues (the slut-shaming potential of this data can't be overstated, especially in a courtroom context. "But your record shows you consented to 5 other sexual liasons in the last 3 days").
Consent is given continually and can be withdrawn instantly. If in doubt whether you have consent, then you probably don't. So ask (again) or stop.