Kudos to the development team Fibre OS is looking good. Installed and set very easily, just follow the instructions. I have never used ubuntu befor and i am not sure how to update the tor browser. First of all how do i get to it once i download it? i did not see any kind of file manager?
Hey , FibreOS is optimized to be fast operating system with quick access to Your cold storage.
However You can install in it anything You want.
Here is the link and install instructions for Nemo file manager
But i think You don`t need this as You are running FibreDark wallet through tor network and can encrypt it with FibreLock pattern which secures You also from keyloggers and other malware. There is no keyboard subsystem being used that malware could monitor! All inputs will come from your mouse.