This seems to be the source for the old package: https://github.com/ZeroPointEnergy/syncthing-click I looked at it quickly - perhaps it wouldn't be hard to update, as it might just require bumping the relevant version numbers. I've never tried to do anything with Ubuntu Touch packages, so I'm not certain how hard/difficult it might be.

@emacsomancer ah, yes, my bad, I copied&pasted the dev name too quickly ^_^ The maintainer of that package is Andreas Zuber, sorry!