Tor: How do I use Tor on Android?

Short answer

Install Tor Browser for Android from a distribution source listed by the Tor Project, then open it and connect. If your network blocks Tor, use the browser's connection settings to select or enter a bridge. Keep the app updated through the same source. An Android browser that merely advertises a Tor proxy may lack Tor Browser's privacy protections.

Sources

Tor Project: Installing, Tor Project: Using bridges.