In Reply to: Try viber posted by Marsanne on Tuesday, 9. September 2014 at 09:53 Bali Time:
I use "line" more than viber but as mentioned you need a good connection. they all work on the same basic system.
Just try to work out where the phone towers are so you get the best reception. Some may post about smartfren sticks and most swear by them.
Remember in the middle of Kuta too many bars Cafe's etc are using the towers for their networks. Most of the time overloaded. Get out of the tourist area near a tower for the strongest signal.