For example a cell phone can stand on a table on the stage or grandstand and another cell phone can control you from the tour.
When the warning button is clicked a message will appear indicating that the time is out.
For a good operation, you must also install a program to mirror the screen of your cell phone in another, there are several that are free, available. Install an application that controls the rotation of the screen, there are several that are free, available.
To find an app to do screen rotation type (screen rotation) in the Play Store.
To find an app to mirror the screen type (screen mirroring) in the Play Store.
Keep the screen in landscape position.
Devices must be connected on the same Wi-Fi network.
Install the mirror and screen applications on both devices, the TempoExato application can be installed only on the device that will control the time.