Steps: 

Install FDroid via their Github here: https://github.com/f-droid/fdroidclient/releases

Open FDroid and go to Settings>Repositories, then tap the + in the bottom right to add a repository.

Navigate to the Guardian Project repository info on another device here: https://guardianproject.info/fdroid/

In FDroid, choose the option to Scan QR Code and scan the code on the left on the Guardian Project site.

Navigate back to the Categories tab in FDroid and search for Tor using the search icon in the lower right.

Install and browse privately.