Running

I started using OpenTracks a couple years ago and ditched runtastic (i keep calling that, it's been adidas running for ages) when I discovered it made my runs public, with gps data and all, for the social features of their app. OpenTracks is FOSS, I got it from fdroid, the data stays on your phone, you do what you want with it. And most importantly it only tracks your activity, just that, no social media crap.

Then again if you don't want to track your runs just don't, I personally do it because I like to see my progression and to keep notes to myself on how/what/when i eat/sleep/etc effects my runs and stuff like that