The Roboto font has been a big part of Android’s visual evolution. It was introduced with Android 4.0 Ice Cream Sandwich, alongside Holo design. It was a transformation for Android, focusing on visuals and moving away from the functional but ugly looks of previous versions.
Over the years, Rotobo has been improved and even gained support for languages using other characters, like Cyrillic. It’s also a part of Material Design, still going strong in the latest version of Android. And now, it has become open source. If you want to check it out, hit up the Roboto GitHub!