I’ve used a few pain tracking tools on and off throughout the years, and by far my favorite is Catch My Pain (https://my.catchmypain.com). It is browser based AND supported on Android and Apple OS. The two products synch together so you can update anytime, and your pain chart on the browser reflects all your entries.
It has the best diagram for marking pain that I’ve used yet- you can draw it on with your finger or cursor. There is a sliding pain scale, list of pain descriptions to choose from, a happiness scale (and stress and fatigue if you upgrade to the pro version). Plus an area for comments.
All of the pain entries come together to make a pain chart that shows area of pain, severity of pain (in % of area, and overall), happiness, and stress and fatigue (with the pro-version). There is a medication option on the phone app, and a diagnosis option in the browser, but I haven’t had much success getting those to work… that said, the developers are great to talk to and are working on fixing the problem.
If you are looking for a pain tracking tool, check out Catch my Pain.