In the past, users would typically download a .jar or .jad file directly to their phone's memory to install the application.
Official support for Viber on J2ME has ended . Modern versions of Viber now require at least Android 4.1+ or iOS . While legacy .jar files may still exist on archive sites, they generally cannot connect to Viber’s modern servers because of updated security protocols and API changes. Technical Specifications (Legacy)
The ability to communicate with multiple contacts simultaneously.
Sending and receiving text messages over the internet.