Ios7 available for iPhone 3?

Sorry not available for the iphone 3G.

iOS 4.2.1 is the last version an iPhone 3G can run.

Regards.

Hello,

is there any other way i can install viber on my iphone 3 , without ios7?

Contact the developer of Viber to see if they have a version available that will

support your iPhone and iOS version. Which versions of iOS are supported is

a decision by the app developer and not by Apple.