Based on the Android Implementation:

https://github.com/opentrack/opentrack/wiki/Smartphone-Headtracking

This uses OpenTrack UDP instead of FreePie UDP

• Windows Phone 8.1
• Way to mount the phone on your head

Gyroscope
The phone has to have a built in Gyroscope for this data source to work. This is the default requirement for your phone.

1. Start OpenTrack app
2. Set Tracker to UDP sender and set Port to 4242 (or any other port). Remember you may need to open this port up in your firewall.
3. Set Protocol to freetrack 2.0
4. Configure Center shortcut in Keys option
5. Configure Mappings based on the Data Source

• Refer to the specific Data Source Wiki Page for mapping and other instructions

6. Click Start

1. Download Windows Phone App and install:

• Stable Version

2. Start the App and enter your machine Ip Adress, the OpenTrack UDP port and Refresh Rate
3. Select the Data Source you will use

• Refer to Data Source wiki page for any additional instructions

4. Click Start to start broadcasting messages to OpenTrack

Now its time to mount the device on your head. The guide on the original Android post works well for mounting your phone. For any other devices refer to the specific wiki page.