From my experience Viber is shi*e - it doesn't work most of the time, one is redirected to "normal calls" a helluva lot of time because of "technical problems" and when it does work calls are being cut off etc. etc. No, it doesn't work. It's a scam, as it earns money for others when you are redirected, in a "quickie" manner, to "place a normal call". Viber might be earning from that, too... Beware!
i've been using viber for about a year now on my pc, it has no technical problems nor strange behaviors so far and i've even made a 3 hours call beside other normal calls, you might want to give it another try but anyway thanks for your info and of course if you don't like this you may use the well known Skype (personally i prefer Skype over Viber )
Using Viber regulary for calling/being called to/from Europe with my phone or laptop. Works very well and never have been redirected to paid calls. So until now I can't share gorski statement. I personally prefer Viber over Skype.
Used it today, the same old story: dropped packets, broken calls on my laptop... Got a call on my mobile - nothing happened... Just not connecting for any length of time... Bah! At my end it is complete nonsense... sadly...
no it's NOT portable, for example it stores the verification code in the registry and the details of your contacts in "AppData\Roaming\ViberPC" plus some smilies.