Connecting to the anonymous Tor network on Android used to require two apps: Orbot, for the actual Tor connection, and Orfox, to browse Tor-specific sites. The developers launched a new browser last year that contained both components, and with that browser now completed, Orfox is being discontinued.
The Play Store changelog for Orfox now contains a message asking people to download Tor Browser:
After nearly a year since we released the alpha version of Tor Browser on Android, the time for sunsetting Orfox has come.
If you still have Orfox installed on your device, this release will direct you to download the new Tor Browser for Android.
Orfox's last update has removed the browser entirely, and now only contains links for downloading the newer Tor Browser from multiple sources.
Orbot, the app originally used for connecting to the Tor network, is still alive and kicking. It can be used to route certain apps (or all network traffic) through the Tor network, so if you're less worried about privacy and just want to bypass website blocks, you can use Orbot with any browser instead of Tor Browser.