Vopium is a mobile VoIP application committed to offers cheap international calls through GSM VoIP or WI-FI connection. If you do have Wi-Fi you can make FREE calls to other users using Vopium in Wi-Fi zone. Vopium also offers new users 30 minutes free calls and 30 free SMS for trial. Vopium is committed to unleash the true potential of voice calls & text messaging for an ingeniously low cost. At the moment Vopium is available in 18 countries as further expansion is planned to provide same clear call quality at much reduced costs covering over 180 international destinations.
Much like Vopium Truphone is a free software to download however Truphone leads its way up with its Skype, Google Talk, and SMS capabilities. It gives you a local number to make and receive calls at local rates
Packages wise it attracts lots of customers with TruStandard (free), TruSaver ($4/month), TruUnlimited ($17/month — you get free landline and mobile calling to US/Canada and free landline calling to 9 other countries, reduced rates for over 50 countries, but calls can only be max. 60 minutes).
Known as market disruptor, skype is an Ebay Company. Skype software for PC and mobiles is used by individuals and businesses who can to make free video and voice calls, send instant messages and share files with other Skype users. With Skype for PC and mobiles users can make low-cost calls to landlines and mobiles. Skype’s main claim to fame is that it allows you to make calls from one computer to another, anywhere in the world, totally free of charge and from mobile you can chat or place a call anywhere through GPRS using its different packages.