Need an app to make phone calls in Turkey

[rgs]

I'll be spending a few weeks in Turkey and I'd like an app to make phone calls in the country. Don't want to change my simm card - there are issues with that in Turkey. I'll be making a few calls to land lines. Viber, Vopium, Truphone - are any of these any good for that or is there a better one?

 

[rgs]

Truphone seems to hit the mark. Works smoothly and inexpensive calls to landlines.