The JO1 OFFICIAL LIGHT STICK by FANLIGHT is a must-have for fans attending JO1 concerts. This free Android app lets you pair your light stick with your seat information to enjoy various light stick performances during the concert. The app has a "Concert mode" that is only available during the concert period.

The app connects to your smartphone via Bluetooth and allows you to change the color of the light stick according to your preference. You can do this by using the color wheel of the app. The app also has a "Self mode" that lets you change the color of the light stick manually.

The app has a "Check Battery Status" button that lets you check the battery level of your light stick. However, this function may differ depending on battery performance and smartphone model. Before the concert, you must check the seat information on your ticket and enter it into your light stick using the app.