As we look forward to seeing how it will continue to evolve over the next 20 years, we're witnessing the Gmail Android app pass a significant milestone, as the Play Store tallies up 10 billion installs.

Granted, Gmail comes preinstalled on a lot of Android devices, but we're not about to let a little thing like that take away from this accomplishment.

Gmail is just the latest in a string of core Google apps that have already crossed the 10B threshold, starting with Play services and followed by YouTube and later Maps.