I love the onesec extension and I've often thought society would be better off if this were the way Apple and Google implemented their app timer functionality on iOS and Android. If you could just mark certain apps as addictive and be given a simple few-second prompt before displaying each of them, it'd stop or soften a lot of the addictive loops, I think. I use onesec app on Android solely to do this to YouTube, but the fact that it isn't native introduces some weird bugs, especially when opening YouTube links from other apps (which I live with anyway, but alas).