You can download the the update directly on your device through the Google Play Store or by using the link which follows:
The Firefox for Android update has the following new features and improvements:
- Support for Android ARMv6 phones with at least an 800MHz processor and a minimum of 512MB of available RAM
- Android (ICS/Jellybean) support for hardware and software decoding of H.264/AAC/MP3 audio and video
- Jellybean support for Explore by Touch
- Android 4.2 instability
- Text deletion issues