Here's a handy FOSS android app with some useful *offline* features for keeping track of your substance use, without it tracking you:
github.com
Available through F-Droid and Droidify:
f-droid.org
This looks like a good harm reduction tool - our thanks go out to the developer!
GitHub - isaakhanimann/psychonautwiki-journal-android
Contribute to isaakhanimann/psychonautwiki-journal-android development by creating an account on GitHub.
Journal | F-Droid - Free and Open Source Android App Repository
Keep track of substance usage to gain insights on consumption patterns
This looks like a good harm reduction tool - our thanks go out to the developer!