Firefox for android is just the regular, stable browser that is recommended. Firefox Beta for android is the next version of firefox that is in beta (still testing, but almost ready) stage and not ready for an official release because it has some kinks and fixes that might need to be made. But firefox beta for android has some of Firefox's newest features that is expected to be released as an official version soon.

The current version of firefox for android is 34.01. The current version of firefox beta for android is 35.0.

There are four main development channels of Firefox.

Release, Beta, Aurora and Nightly.

The most you will likely want to use is Release and Beta. The Aurora and Nightly channel are more for testers/devs as they usually get updates everyday so therefore they get updates each of those days.

Currently Release on Android is 34.0.1 however as early as Jan 13 the Release will be Firefox 35.0 and the Beta channel will then have 36.0 which moved/merged from the Aurora channel.

Beta builds (where there can be six to twelve builds for a version) is usually stable to use though the first few builds can sometimes have some issues initially. You likely have the 35.0b11 build.

Ererer said

The current version of firefox for android is 34.01. The current version of firefox beta for android is 35.0.

34.0.1 and 35.0b11