In iOS, you have “floccus”
Its the same thing as Xbrowsersync, unless with Xbrowsersync the bookmarks are saved encrypted in their server, and with Floccus its saved encrypted self-hosted (so you store it in your webdav, gdrive, or nextcloud instance for example)
Its also cross platform, iOS Android and extensions for chromium based and firefox based browsers
And the project is actively maintained, new updates every month, the developer is nice and always trying to give more features and security
I’m sharing this because I use it everyday, I found it wonderful, and I think for some people it can be a better solution than xbrowsersync
Open source of course.
And I find the UI easier to read, easier to look for a bookmark. On the mobile app, there’s definitely more bookmarks that fit in the visible screen. But I guess that’s personal.