Your NFC tag is made to open up an app when your device is near. It loads over other apps like the Google cardboard app, etc. The only way to change that behavior is to re-write the NFC tag. To do so, you get some free writing software for your phone and program it to do whatever you want. This could be launch the Google Cardboard app or anything else you want it to do.
The NFC tag is designed to work with phones that have an NFC receiver. Each phone handles the interaction differently so be sure to research your individual make and model. Make sure your phone is set to allow (or block) trigger events from an NFC tag. This can be found in your general setting, but each device is set up differently.
The tag included in the DODOcase Smartphone VR Kit is programmed to launch the DODOcase VR app (www.dodocase.com/vrapp). Since many apps can inadvertently be closed by an NFC trigger we programmed our app to have a 15 minute 'quiet period' after the initial trigger. So, if you hear a noise, but no action chances are you are in the quiet period window so just wait 15 minutes. Remember, you can always open apps the old fashioned way with your finger!
If all else fails or you wish to have the NFC trigger another event, we have given you a high capacity tag that can be re-programmed to do anything NFC is capable of. To reprogram, use a tag writing app such as NXP Tag Writer.
Additional information may be available in our VR Forum: