When I visit any form hosted by kobotoolbox within any browser, I can create a direct access to it (added to “start screen” on the device). Although the name of that direct link can be changed, you can not change the icon (right?). It just grabbed the default icon of the Kobotoolbox’s web application. There is any way that you can allows this icon to be changed (for example, some special field on the form)? (It is a rare question, I know)
Yes, the icon is set by default. If you however wish to change the icon you could do it as outlined here.