Tekne
Tekne is a freestyle productivity app in the shape of an outline editor.
Freeform data over time
Tekne's core feature is that it allows you to track data over time in a free-form way.
Tag data with #tags and get an aggregated view over time automatically.
Under construction
Tekne is alpha software that's changing on a weekly basis.
The best place to learn more is the tutorial and documentation in the app.
Check out the demo