Close button on settings popup

[marvinjuette]

Is your feature request related to a problem? Please describe.
If you want to close the settings popup on mobile, you need to click somewhere on the screen outside the popup. However, due to my screen, the space between popup and screen edge is very small so it is pretty annoying to close this settings menu.

Describe the solution you'd like
A close button on the top left, or top right corner would be enough, because it is always visible, can be used on all devices and its usability is not bound to the screen size.

Describe alternatives you've considered
Maybe a close button at the bottom of the dialog? But since it would be a text button, I think it might not look as good as a simple "x"-icon for closing the menu.