YouTube Go is now out of beta - A super-lightweight and Offline version of the YouTube app for Developing Countries
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.
Before you get excited, it's still only available in a handful of countries, such as India and Indonesia. For everyone else, you can download it from APKMirror.
See http://bit.ly/2Aeryf6 where there is also a link to the APK file.