Currently, it's not possible to toggle the state of Torbutton in Fennec. Mike suggests that by manually configuring the proxy settings, it is possible to cause Torbutton to "kick in" and start protecting the user.
I was able to enable Torbutton by manually setting the following to match the normal Torbutton settings for the following:
network.proxy.http
network.proxy.http_port
network.proxy.no_proxies_on
network.proxy.socks
network.proxy.socks_port
network.proxy.socks_remote_dns
network.proxy.ssl
network.proxy.ssl_port
network.proxy.type
With those network.proxy keys set, I was able to route through Tor to check.torproject.org!
It appears that those settings are wiped out if Fennec crashes. It is tedious to reset each of them. Additionally, Fennec has a bunch of errors in the debug console. Ingy has suggested that he will copy them out of the Fennec emulator.
Attempting to install Torbutton in the Fennec emulator totally fails. It may be a difference between the nightly build for Android and the current emulator build. Fail city, Population: US
As I say in #5709 (moved), I think the best way to do this is to gradually transfer more and more important bits of Torbutton over to ProxyMobile. There's a lot of useless cruft in Torbutton from toggling that is no longer relevant to anything, and only serves to make this port more difficult than it has to be.
We should take only what we need and abandon the rest.
Trac: Keywords: android orbot torbutton fennec deleted, N/Aadded Summary: Port Torbutton to Fennec to Make ProxyMobile more like Torbutton
I've updated #5965 (closed) with a patch commenting stuff to port over to ProxyMobile along with priority levels. I'll be merging it to torbutton's master soon. Comments to make it more useful appreciated.
We do still have Proxy Mobile available, along with a list of 10 other privacy-enhancing steps you can take with Firefox Mobile:
https://guardianproject.info/apps/proxymob/