The NFC Tec application allows your smartphone to write NFC tag (camera Wai-Fai Music control etc.).
Just touch your smartphone to the NFC tag and perform a task.
If your smartphone not NFC compilable so not write NFC Tag. So first check your smartphone NFC compatible.

How to check smartphone NFC compatible "Yes" or "No"-:
Step 1-: Read device connectivity specification or Go to setting and check.
NFC Tec application easily write task you NFC tag after write tag close the app and easily tap NFC tag near your smartphone NFC sensor. If your device NFC support and NFC open task easily perform.