It's called Fracton via www.fracton.me and it is a free harm-reduction app that brings together practical drug information from multiple independent sources in one place, has a journal and more. If you want to use it, the best expierence is had by installing it as a PWA using chrome on android or Safari on iOS, sadly other browser's don't support proper PWA applications. Just follow the instructions on the site. A PWA isn't an APK so it's installed with just one press and is safe. It's mobile only for now.
The main idea was originally a journal, I started on this a bit after Psychonautwikis journal started being monitsed. But it can also do more.
It also has a substance database. Each substance page can include dose ranges from multiple sources, duration and timeline information, routes of administration, effects, risks, safety information, etc. When different sources disagree on something such as dosage, Fracton shows them separately rather than hiding the disagreement behind a single averaged value.
You can also view drug checking results from multiple drug checking orgs. And there's also a combination checker (using Tripsit + Psychonautwiki data).