For context: Exist is a personal analytics platform where we import data from sources like fitness trackers, Apple Health, productivity trackers, email and calendars, social media etc. and find insights and correlations in the data. We've been doing this for about 3 years now, and we've just added the ability to track your own tags, probably our biggest feature release so far. These are just binary yes/no tags you can add to a day for context, like "coffee", "sex", "meditation", or whatever you like. We can then use those alongside your other data to find correlations like "you have a worse day when you track 'nootropic'" (which was the case for me), or "your weight is higher when you track 'eating out'".