We began developing Sync during our "Muon" days, when our browser was a fortified fork of the Electron project. We then moved over to "Core", which is a soft-fork/patch of the Chromium code-base. As such, this required us to back-track just a bit, and recover some ground. Efforts were then directed at shipping a MVP of Sync across Windows, macOS, Android, and iOS. We succeeded in doing that not too long ago, and are now working towards expanding support for more data types. Hope this helps!