What should we keep in mind when developing a (simple enough) GUI for both mobile and desktop?

[enjoysmath]

I'm looking for suggestions of what to use / what not to use in general when working with Qt Quick. For example "Don't use this qt quick item because it is too complex for displaying on a phone". Etc.

[sierdzio]

Nothing really serious comes to my mind, and I have worked on many desktop and mobile apps in QML.

Just some general remarks, then:

• mobile UI often makes little sense on desktop. It looks weird, very different from other desktop apps, and very often does not take advantage of large screen space. Having separate UI for desktop and mobile (or phone and tabler+desktop) is often a good idea
• when on desktop, add scrollbars :-) On phones people know that lists are flickable. On desktops, it is not immediately obvious to many people, that a list can be scrolled
• remember that notifications are far less noticeable on desktops (just a small balloon in the corner of a screen, and it disappears quickly) than on mobiles (persistent entry in notification "log")
• remember about keyboard ;-) On desktops it is very useful to have keyboard focus, proper tab order etc.