Papaya - turns your phonebook into a fun and useful social network! It allows you to communicate with your friends cheaply and easily, no matter where you are. Using Papaya, you can play games with your friends, chat with them over IM, share pictures and other files, make cheap international calls, and more
VoipCall is a similar program like VoipSMS, instead this one if for calling someone.
Instructions:
In order to use VoipCall, it's important to configure it first.
Go to options and set the following values on the first tab (Application Settings). Pause sign: p (lowercase, this is default, however unlikely your phone might have a different sign)
With S-unno, you can use your Windows Mobile phone to make phone calls to any fixed or mobile number in more than 200 countries at absolutely low rates. Rates start from as low as US 1cents/minute. S-unno uses your 3G or WiFi connection to place these calls so that you can start saving now
X-Lite - Soft SIP VOIP Phone - A Free SIP-based User Agent [IP Phone] with all the features of a standard business telephone. The intuitive design and familiar layout provides for easy navigation. Already tested with Toshiba, Dell, Compaq/HP, Audiovox PocketPC devices
4Talk is the easy way to turn your Pocket PC into a two way communication device suitable for short range transmissions. Pair two or more Pocket PC's to create a mini walkie talkie network, or use it in conjunction with your PC to create a continuous surveillance or baby monitoring device
SJphone - SJphone is a VOIP softphone that allows you to speak with any other softphone running on a PC/PDA, any stand-alone IP-phone, or using Internet Telephony Service Provider (ITSP) with any traditional wired or mobile phone.
It supports both SIP and H.323 standards and is fully inter-operable with most major VOIP vendors and ITSPs
