PC-Smartphone talk relay software

Many mobile phone service providers around the world are offering free talking plans for a modest monthly pay for family members, but that generally doesn't apply for international calls. Couples living different continents may want to communicate using cell phones as cheap as in the same country. It could be a good solution if the data transfer speeds were high and costs were low, so one could simply use Skype directly from one's phone, but that's not always the case.

So, the idea is for both distant family members to order the family talking plans in their respective countries, then for each to leave a smart phone at home connected to computer. Write the software for the components to interact, so that when you call to the phone left at home, it would start calling a particular contact on Skype, and when the other computer received Skype call from you, it would use the phone connected to it to call to your family member abroad.