LG U TV 리모콘 is a smart remote control app that supports LG U+ TV with infrared sensor support. This free app allows users to control their LG U+ TV through their smartphone. However, it is only compatible with Samsung Galaxy S series up to S6, as Samsung stopped providing infrared sensor support from S7 and above.

To check if your smartphone model is compatible with this app, there are two ways to do so:

1. Search your smartphone model name on the internet with keywords such as "infrared" or "IR" to see if it supports the app.

2. Look at the top edge of your smartphone with another camera (not the one you want to use for the app). Press the buttons on the U+ TV remote control app, and if you see a light, then your smartphone is compatible with this app.

Infrared is not visible to the naked eye, but it can be detected by cameras and other devices.