Turn This Off On Your Viber To Avoid Roaming Charges

When traveling and you want to avoid bill shock from roaming charges, you can use Viber for calls, especially when there's wifi (say, in a hotel).

Just don't forget to turn off "Viber-In Calls" on your settings. If you keep this on, your Viber calls could be diverted to regular roaming calls, with roaming charges.