You just need to create a dial up connection No need to download any software. Go to the site and update the password daily.
ipkall has been overused now unfortunately. Therefore, I do recommend if you have some spare time, try to register 2 to 3 for your use.
1. for OBi110
2. for asterisk server if you have
3. for iphone or other free voip apps that can make use of GV
This should be enough for your everyday usage i.e. home, mobile +/- pbx.