I'm new on this forum, as I stumbled upon it while trying to figure out an answer to my problem.... My boyfriend just got a smart phone (Galaxy 3) and I have an iPhone 4S. We both installed Viber yesterday so we can actually talk to eachother for free, but it's not working. His current SIM card is for Germany (where he is currently located), and he is listed in my contacts by both his German number and his Croatian number. (I am located in the United States.) However, he is not showing as a Viber user on my phone (there are six people in my contacts list showing as users, but he is not one of them), and when he tries to invite me, he says it comes up as me not having installed the app. I went to the Viber website and tried ALL the trouble-shooting options listed. (Deleted him and re-added him to my contact list, turned my phone off and on, closed and re-opened the app, sat right next to our wifi box to make sure the signal was super strong, tried putting in the country code more than one way - with an without the zeros.....I even uninstalled and re-installed it.) I'm not sure what else to do! Please help! Thanks!