Now the mobile Tor Browser, named Orfox, has finally added this feature. In a blog post, the Tor organization explained that this is the first major step in making Orfox and Tor Browser identical in functionality. Both browsers are based on Firefox, with special modifications made by the organization to increase security and privacy.
You can grab the latest version from F-Droid, GitHub, or the Play Store (at the link below). You'll also need to download Orbot if you don't have it already, which is required by Orfox to access the Tor network.