What's the best Rails gem to create a database dashboard with graph and radio buttons like these photos, knowing that I'm still newbie in Ruby On Rails.
The administrate repo is well maintained, have a look at it. If you need more, a dashboard is mostly CSS, abit of JS and HTML. Grab the AdminLTE template and work with that. It should cover most of your needs. There are afew of it that should get you on the ground running.
Happy hunting