The following review written by one of the Software Informer contributors applies to version 4.1
As phone calls over the Internet became very popular, the client software for them progressed as well. LowRateVoip allows you to make long-distance phone calls, to both mobile and landlines all over the world. You can also send SMS messages through it.
The program itself is freeware, but in order to use it, you have to pay for calls. It's the same system used in prepaid mobile phones: you need to pay a certain amount of money, then you spend it on calls. Besides low costs, first month is free after you have paid, which is a pretty good deal.
Installation is very simple. The first thing you have to do after you install the program is to create an account. Once logged in, you can start calling by typing phone numbers or adding people at contacts and selecting from your contact list. There are options to import phone numbers from Outlook contacts. Contacts can be organized in groups too, which will ease their management.
I have used this application for the last two years and the audio quality seems very good to me. During longer calls, the connection gets dropped sometimes, but it only happens once in a while and is not a big problem.