To sign on a touch screen, just open a case on a computer with touch screen, a smartphone or tablet.
Choose Sign now and sign on the screen using your finger or a stylus pen. You will be asked to rotate screen to sign. If your screen won't rotate, please make sure that your rotation lock is deactivated on your device.
For many, it might be the first time writing your signature on a touch screen. If you want to re-do your signature, just press the arrow in the top right corner.
When you feel happy about your signature, press Done and you're done!