After seeing the demos and reading the documentation of the multilingual add-on, I believe there should be a flag on the right side of the edit bar just next to the dashboard button. This button should allow me to switch between different version of a page for each language. Unfortunately I can't see it, nor on my deployed website nor on a fresh new install of C5 locally (both are 4.2.2). Everything else work as advertised, including the "choose language" flag block.
Nobody seems to have encountered this problem so I am a bit puzzled it shows on 2 different environment including a fresh install with only this add-on.
Hopefully, there is an obvious checkbox hidden somewhere to show the flag button and someone is going to tell me how blind I am...