Hi Thank you for your question. This is a tricky one to answer. The number of downloads for both Firefox for Android and Firefox for Android Beta are available from their respective pages on the Google play store, but I appreciate this does not include people that install Firefox directly onto a non-Google version of Android, or those (like me) that use Firefox Nightly or Firefox Aurora test versions. With regards to Chrome on the Android platform, it is worth considering that this is installed by default on Google versions of Android, possibly on of the most popular operating systems on the planet. As a result this comparison may show an unfavorable position, but one that could be said to be very unfair.