In the early 2010s, the mobile world was split into two distinct camps. On one side were the emerging smartphones—iPhones and Android devices—with their touchscreens, app stores, and always-on internet. On the other side were the hundreds of millions of feature phones running on Java ME (J2ME), the once-ubiquitous platform that powered devices from Nokia, Sony Ericsson, Samsung, and LG.
Many files labeled "Viber.jar" on mid-2010s mobile download portals were actually: Viber For Java J2me