Apparently, there is a way, but it is not for the faint-hearted. I have a similar thread here.
The Ubuntu touch 'click' packages
You can use adb shell to install click packages, once you find those packages and are happy about their origin.
To get adb installed, you can follow the "Prepare your desktop" section of the ubuntu touch installation howto.
Once you have adb, enable debugging on the device (System settings, About, Developer mode = On), connect the device using usb and run on your host:
You'll get a listing indicating that the device is offline. Don't despair, there will be a confirmation dialog shown on your device to allow the particular host to access the device. Once you confirm, the device will talk. Then run:
This gets you shell access (and root through sudo) to the tablet. You can then install ANY click package. Any that you can get hold of, which is somewhat spookey...
pkcon install-local --allow-untrusted FILES
I've been advised that you can compile the click packages from source, but I'm hoping to figure out some simple way to locate the distributed free sw packages.
You can switch the filesystem to write mode (careful, there be dragons!) and do the usual apt-get things. You know it's not advised because that will render your system unsupported by automatic updates and you risk losing your modification. Heck I can live with that...
I have found another interesting resource on using custom made app container with Libertine. I haven't tried that myself yet, but it might give you some ideas. Here's some introduction to libertine containers.
... I wonder! To answer your second question, why is it compulsory to have the 'one' account, I can only plot some assumptions for you:
- It is work to do to support anonymous operation, so it hasn't been done yet (my hopeful favorite)
- The authors actually do want to track you for what ever reason (I wish this is not the case)