>For a simpler approach, more akin to downloading a piece of software and running it on top of your operating system, please wait for our Electron-based app bundle later this year. [1]
Hope soon they release the downloadable app and is possible to use it locally/offline/without account (like Inkscape, Gimp, LibreOffice).
I guess that right now is no free and open source tool that cover specifically digital interface design, you can do it with Inkscape but it has so many more unnecessary features (print mostly), and no prototyping, components, developer handoff. Pinpoint seems to be going in that direction (Figma features) and with a good UI/UX approach [2]. Exiting!
It will open the door to designers who can't pay for Adobe XD/Figma subscription. Hope they will be able to sustain the project with his paid cloud/teams service (a la LibreOffice).
For the interested, just added to my RSS reader the repository to stay updated about new releases! (the blog seems to not have rss) https://github.com/penpot/penpot/releases
[1] https://help.penpot.app/faqs/#how-can-penpot-work-offline