Microsoft’s decision to expand its Office suite to mobile platforms like Android and iOS has been a great decision so far. Recent new found that Word for Android has been installed more than 1 billion times since it was available on Google Play back in 2015. That means that there is almost as many Word installs worldwide as there are Windows users.

Now these numbers are huge but some are pointing out the large contribution could stem from the agreements that Microsoft has with some manufacturers to preinstall the apps on various devices. Aside from Word, the company’s other apps are doing pretty well also. Excel, PowerPoint, OneNote and OneDrive each have more than 500 million installs while Outlook for Android has more than 100 million installs.

Just last month, Bill Gates mentioned that his greatest mistake ever was missing out on the mobile OS world, noting that there’s only space for one competitor for iOS, and that is should have been an easy win for Microsoft. While the efforts of Microsoft have never reached the success of its competitors, its mobile versions of Office can now enjoy a significant amount of market penetration.