I’ve used a Bluetooth heart monitor worn around the chest (was around 20 $ ten years ago) to measure the heart rate before. It works well with open tracks and should be more reliable compared to a device worn around the wrist. I am not sure the gps tracker on a watch works be better than the one on your phone anyways. It might be a problem with your phone killing background apps like opentracks. Check https://dontkillmyapp.com before pulling the plug on a new device.
https://www.messenger-matrix.de/messenger-matrix-en.html
^^ Good comparison with other IMs.
Here is a good overview. You could compare this with your findings:
If you do not need the nfc cabability of your cards, just his them in front of a bright lamp, see where the cables run and cut the card with a scissor. Apply transparent tape over the cut and you have a privacy respecting card again. It’s what I always do as my bank offers no service to disable nfc.
I get exactly the results for reddit.com and old.reddit.com
Start here for a good privacy focusef overview of currently available internet messengers:
https://www.messenger-matrix.de/messenger-matrix-en.html
From the blog entry by the same author:
Cons: no verification of contacs possible at the moment, Increased battery usage compared to other messengers, some client instabilities, no full security audit.
Apart from these points the messenger should be secure and privacy friendly.
I prefer the conversations (xmpp) messenger at the moment. It’s using a well established and lightweight protocol (20 years old already)
I’ve been using xmpp for several years now. Even running my own server for family and friends. It’s a great feeling to be fully independent imho.