Hello,
I made a data field in 2021, to help me with ultra-distance cycling. I didn't really know what I was doing, but it seemed to work pretty well. Like most people I found the dev process pretty clunky, even if the code itself is easy.
In the last few days a user contacted me with a query about inaccurate data (it's now 2025). That prompted me to learn a bit more, rewrite the app, and republish it as a new version. It's been an informative process, though I readily accept I still don't know very much 
Anyway, I have made my repo public. In particular I found writing and using tests hard to figure out. So hopefully this can help someone else.
https://github.com/thisdougb/SinceStopped
What I was able to do was take scenarios where my data field appeared to be incorrect, and generate Activity.info data to replay those scenarios as tests. So I can generate 5 minutes of movement, then 2 minutes of stationary, etc. Because I am supplying the time as a value, the tests run near instantly.
Once I figured out how to use tests to replay scenarios it made the dev process quicker because I didn't have to rely on the simulator. I still don't really understand how to get the simulator to function predictably.
