Assuming you already have Chromium installed…if not…
$ apt-get install chromium
This tended to work for me on PureOS:
$ wget -q -O - https://www.ledgerwallet.com/support/add_udev_rules.sh | sudo bash
However, it seems that every once in a while, Chromium doesn’t load correctly, so you need to run this if the browser does not start correctly:
$ chromium --disable-extensions
It’ll then load Chromium without extension support. Then close Chromium and reopen normally (without the disable extension flag). It should have the Ledger Apps/Extension support now (note, you need the Chromium Apps installed too which is available from the Ledger Wallet site: https://www.ledgerwallet.com/apps).
This happens to me on/off, so I have to sometimes run it with disabled extension support first, then reopen Chromium as I’ve mentioned above every time I want to use it. I noticed too, Chromium has a problem loading the libcanberra gtk module, so if you do this, it should help:
$ sudo apt-get install libcanberra-gtk*
From a software perspective, this is all I needed to do to get it working.
From a hardware perspective, you need to disable browser support for some reason for it to work. Your device also needs to be in “Use wallet to view accounts” mode else the Chromium App will not initialize it correctly.
I hope this helps.
Note, if you use Google’s Chrome version you don’t have this app/extension problem. But that kind of defeats the purpose of using an Open Source browser.