Just Dance Controller

Just Dance Controller (Formally known as Just Dance 2015 Controller) is a free app by Ubisoft where players can use a smart phone and play (only on the Xbox One and PlayStation 4),,  , , and  for the Wii U, Xbox One, PlayStation 4, PC, and the Nintendo Switch (the PC version is only compatible with the app for Just Dance 2017). The app was an update to the Just Dance 2015 Motion Controller.

How it works
'This app is only compatible with the Xbox One, PlayStation 4, PC, Wii U, and Nintendo Switch versions of Just Dance 2016, Just Dance 2017, Just Dance 2018 and Just Dance 2019'' (PC is compatible with the app for only 2017 and Nintendo Switch is compatible with all apps since 2017). However, on Just Dance 2015, the app is only usable on the Xbox One and PlayStation 4 versions of the game.'''

With the use of the app, the phone can be used as a controller to count your moves. The phone will work similar to that of a Wii/PlayStation Move/Joy-Con remote. The app also allows you to select the songs through the phone. It also makes a sound when you achieve a star or perform a Gold Move correctly.

Trivia

 * This is the third app made by Ubisoft that is related to Just Dance. The first one is AutoDance and the second one is Just Dance Now.
 * As mentioned before, this app was an update for the Just Dance 2015 Motion Controller app, as it works with Just Dance 2015 as well, but only on PlayStation 4 and Xbox One, just like the Just Dance 2015 Motion Controller app. The update just adds support for the Wii U, PC, and Nintendo Switch consoles for later Just Dance games.
 * In Just Dance 2016, if the game doesn't register moves correctly and counts them as multiple Xs, the game will disconnect the phone in order to refresh it and calibrate the phone for more accurate tracking.
 * On Just Dance 2015, an update for the game is required in order for the app to work for the game.
 * The app mainly is used by Xbox One players without a Kinect, PlayStation 4 players without a Move or Camera, and Wii U players without a WiiMote.
 * In an update on the Just Dance 2016 version (Version 2.2.0) of the app, the Ubisoft logo animation movie was added but it mistakenly have the logo music from Just Dance 2015. This was later fixed in a later update (Version 2.3.2). It was later being removed in the 2018 version (Version 4.0.1) due to the new Ubisoft logo revealed in the UbiBlog on May 31st, 2017.
 * This app is required for PC players in.
 * The game can be played without the app. When that option is selected, players won't score. However, there is an option to connect the phone to the game.
 * On The Coach Selection screen, it shows a warning that no phones are connected and scoring is not possible. And the starbar is removed during gameplay.
 * In the Just Dance 2018 version (Version 4.0.1) of the app, the photo booth option was removed.