New userscript Android browser available: Iceraven
It has been a long time since new Firefox for Android 79+ (Fenix) broke the add-ons.
I was staying in version 68.11.0 (Fennec?) for that purpose, hoping either Firefox would restore add-ons or Vivaldi would eventually support extensions.
Apparently, there are still only 13 allowed add-ons on Firefox for Android, and still no trace of monkeys (Grease/Violent/Tamper).
Hopefully, thanks to a post in Vivaldi extension support request topic, I heard about a Firefox fork with add-ons support: Iceraven Browser!
I was reluctant to install a somehow insecure for me unofficial browser, but it seems now to be the only good solution for Android, I went for it.
I uninstalled Firefox 68.11.0 and installed Iceraven, and it works great for the moment (I only tested COLLECTION HIGHLIGHTER).
As it’s a Firefox fork and as add-ons works great on FF 68, I think everything will be alright.
There is just a Cannot Complete Request small glitch when you install a userscript but don’t worry, the scripts are still installed.
Update
I have had some hindering bugs with userscripts on Iceraven so I’m still staying with Firefox 68.11.0, at the moment.