Generally, it takes a few seconds for the syncing process to be completed, so please be patient while the InPlay app attempts to sync with TV audio. If after 30-40 seconds your device still has not synced, please check that you are watching the correct channel and the volume is turned up to a reasonable level.
You may want to place your mobile device's mic near the TV speaker. The game needs to sync with audio from TV with cable or satellite. Tuning in with internet streams will not work, or will not work as well as TV.
If you still have problems syncing it may also help to press the home button on your device, and then go back into the app, which will allow it to sync again with the live game audio.
Also try turning off your WiFi, cellular settings or going to airplane mode. You can find these options within your settings menu on your device. Once off, then immediately turning them back on again should help.
If the problem persists you can re-download the app from these links below. Doing this will confirm you have the latest version installed.