Chrome Web Store: https://chrome.google.com/webstore/detail/windows-timeline-support/meokcjmjkobffcgldbjjklmaaediikdj
Firefox Addons: https://addons.mozilla.org/en-GB/firefox/addon/windows-timeline-support/
Source: https://github.com/DominicMaas/TimelineExtension
Honestly, i’m pretty blown away by how well this works already despite it technically being a beta/initial release.
I initially disabled timeline after installing 1803, but this made me re-enable it. I haven’t tried see if this works cross-platform, i.e. opening up the synced items via the Microsoft Launcher on Android. Would be amazing if it works!