[EEGator]

http://digwhich.com/blog/2015/3/18/use-ipad-as-phone

[Yosemitest]

Thanks for the link.
It's a good read.

Note: Be aware that these apps use a data connection (either over wifi or cellular) to send and receive information, and may increase the amount of data you use every month if you're using them over a cellular data connection.