1) Download Infinit from here.
2) Open the .dmg file after it has finished downloading.
3) Double-click the installer to automatically install Infinit in your Applications folder.
4) Because Infinit is not on the Mac App Store, accept to install it on your Mac.
5) Open Infinit from your Applications folder
6) Read the tutorial to discover how to use Infinit.
7) Log into Infinit from the menu bar icon.