If you are holding an older device, such as the iPhone 3G or the original iPad, and trying to get Viber working on iOS 4.2.1, you are likely facing a common frustration. While finding the .ipa file (the iOS application archive) is possible, getting it to work is a different story.
You need an older version of Viber, such as , which was the last to support iOS 4. Viber .ipa for ios 4.2.1
iOS 4.2.1 has excellent jailbreak tools (greenpois0n, redsn0w). Jailbreaking allows you to bypass signature checks and install any .ipa using tools like iFunBox or iPhone Explorer . If you are holding an older device, such