A Mac app that let you dial phone calls via AirPlay. Needs OS X Yosemite and iOS 8 on your iphone.
This project uses libphonenumber. You could download it from here. Put libphonenumber.a under /opt/local/lib or anywhere you like, and update linker options in XCode.
Pre-compiled binary is available here
Open it, dial, and that's it.
You may need to activate Facetime with your Apple ID on your Mac first, and put your iPhone and Mac under same WiFi network. AirPlay must not be turned off. A simple test is, when your get a call you should be able to answer it on your Mac.
This project is under GPLv3. See LICENSE.