I am struggling to understand and use ‘popups’ in the new v3.0.1. I am assuming they are new to v3, since I cannot recall seeing them on my previous v2 … but I could be wrong. However, to describe the problem. I am highlighting a text expression and choosing On Click / Open Popup and selecting an image as content. Please see upload. This works fine on my preview screen - the picture comes up and then can be switched off via the ‘cross’ svg. The problem I have is that I now cannot use the Sparkle app any more, since I cannot click away from the picture! The only way I can find to make Sparkle operational again is to delete the picture, which of course nullifies everything I have done and defeats the object of the exercise. I must be missing something here. Please help.
I suggest you take a look at this example, there are a few tips on how to use the popup that maybe you are missing:
Thank you Duncan. OK … it has all now become clear. I had absolutely no idea that the ‘popup’ icon (on the top mini-menu bar) was there, but perhaps I should have looked a bit harder. It was the ‘Close’ button that I failed to see which switches focus by dismissing the popup box! This is of course the solution to my query/suggestion a short time ago regarding the ability of text to bring up (or more correctly ‘pop up’ 
) an image or picture. The whole thing is quite sophisticated and has so much potential. I will be using this facility extensively from now on.
I agree with the suggestion from mOehlschlager regarding a section in the written documentation and a video tutorial.