So,what’s the issue?
Don’t know their phone number?
Ok.We would suggest you to try out this new apps named(OnSay).
What it does?
OnSay is a free application that lets you make free calls without a phone number to your Twitter friends.
Easy To Use:
All you have to do is just download its apps on your iphone from appstore.Once you download the apps then log in with your twitter a/c.
Now look up for those friends who are on twitter (and invite them to install OnSay apps).Once your twitter friends install the apps then you can make a call without phone number.
It’s free to download and free to use.No charges for using its services.