The following review written by one of the Software Informer contributors applies to version 4.0
Jumblo is an application that makes it possible to phone people around the world, and send sms messages to any mobile phone. The phone calls and sms messages are sent via the Internet.
We need to have a broadband Internet connection, a microphone, plus a speaker (or a headset). We can also use our local/mobile phone to make VoIP calls.
This application is free to download and use for chat purposes, as we are only to pay for the phone calls and sms messages. The good thing is that the cost of the calls/messages that are made via Jumblo is usually much lower than the cost of those made using the common phone network. Depending on our location, this Internet-based service gives us the opportunity to make local phone calls for free, although this possibility is offered for a limited amount of time every week. To make use of this free bonus, we need to have enough credit on our account.
The interface of the program, which is quite user-friendly, enables us to import/manage contacts, set our own avatar, use the dial pad, switch the language, chat with other users, restrict incoming calls/chat, forward calls to a local phone, or to another user, and much more. There are two other Jumblo editions: one for Macintosh/Linux, and another for mobiles phones.