If you are not able to detect your computer using the AirParrot Remote app, please first ensure that the device is connected to the same wifi network as the computer. Also, double-check that you have the latest updates for AirParrot 3 and also that AirParrot 3 is running on your computer when attempting to pair AirParrot Remote on the iOS device to AirParrot 3.
If this all checks out and you continue to have trouble, you may need to try using the Quick Connect code to pair your device. Some more details on using Quick Connect can be found here.