Earlier this year, Google released 'YouTube Go,' a super-lightweight version of the YouTube app tailored for developing countries. You can download videos in varying qualities, and then send the local copies to nearby friends over Bluetooth. In areas where a working (let alone fast) data connection can be hard to come by, these are welcome features.
Google has been continuously working on the app since it soft-launched, and now the app has left beta. Since we first covered it, the UI has been modified to closely match the full YouTube app, but the functionality hasn't changed much.