I use a somewhat old #V800 sports watch (what a joke, it's 10y old and #Polar does seem to have stoped support for it). I use it offline by downloading its data to my Linux notebook. While on vacation I could do the same using the same software stack on my mobile phone: a #Librem5.

Once in a a while I still get this feeling how amazing it is to have a small Linux computer in my pocket - even though it is already since more than a year my only mobile phone.