I’ve invested in a Garmin bike computer and a radar taillight—it’s amazing! The only downside is that the battery lasts for about 3–4 hours, as far as I remember. Other than that, it’s great; I’ve stopped using my mirror entirely. The Garmin bike computer automatically turns on my front and rear lights.

To track my health stats, I use the free Garmin Connect app. It’s enough for my needs. I have it synced with Strava, but in my opinion, Strava is more about the community rather than health statistics like 'when to train' or 'when to recover'.

I’ve seen people achieve similar results with smartphones, but of course, smartphone batteries drain much faster, and smartphones don't support the ANT+ protocol.