All you really need to do is to make your call like you normally would!
Step 1:    Select your friend’s number in your phone book and press call.
Step 2:    Select Hoiio to make the call when prompted
Seamlessly, Hoiio in your mobile phone will send both your number and your friend's to Hoiio's hosted system. Hoiio's system will then call both numbers and connect both calls.
Step 3:   Wait for Hoiio to call you and accept the call
Voila! Your outgoing call has been converted to an incoming, and you can now enjoy long conversations without worrying about chalking up the high expenses of outgoing calls.

Because incoming mobile calls are usually very cheap or even free, you can save more money compared to making outgoing calls, If you are making overseas and roaming calls, Hoiio's Callback is the perfect solution to help you save LOTS on your mobile phone bills.