Hello and welcome at the Fairphone community.
There a two parts of Android OS available for the Fairphone. The first is “pure Android” with no modifications made by Fairphone (the Company) the other one is Fairphone OS this is a lightly modified Android Version witch is supportet by the company Fairphone. In general you should use the Fairphone OS.
Version 1.6 of Fairphone OS is the one you should use at the moment. 1.7 was just a test Version preinstalles on a view devices. I am verry happy with version 1.8 but the updateprocess from 1.6 to 1.8 was a little problematic, so Fairphone decided to postpone the Update while they are fixing the Problems with the Update process.
If you don’t like the Launcher because thinks are hidden you might be interested in this Topic.
regards,
Shiny