You can control your locomotive using the volume buttons on phones and tablets. This way you do not need to hold the phone front of you and watch the screen and tap the speed control buttons. You can just hold your phone in your hand next to your body and press the volume buttons to control the locomotive while you do not have to look at your phone instead watching your loco moving on the layout.

Volume up: increase speed with one speedstep
Volume down: decrease speed with one speedstep
Long press volume down: emergency stop locomotive

If you use a physical keyboard on your laptop, you can control your loco with arrow keys:

Up: increase speed with one speedstep
Down: decrease speed with one speedstep
Left: change direction to backward
Right: change direction to forward

Note: on screens, where two locomotive is visible above each other, only the top locomotive can controlled with buttons.

Note: locomotive control with volume buttons does not work on IOS devices.