Hi @kamilfurman, thanks for checking in. In summary, we thought we were close to getting out Desktop apps with some offline functionality, but in the end are not able to do so, and are reverting back to our original plan to just release desktop apps without any offline support.
As part of releasing online-only desktop apps, we also had to make some much-needed improvements to the Supernotes backend API, to allow for things like not having to login every 3 days (and much more). All of those changes will be included in the upcoming Supernotes 1.8 release, which is when we plan to release the Desktop apps.
I use Supernotes every day and myself would really like having a desktop app, so rest assured that we are working on it and will get them out as soon as everything is ready!