Thank you Robert! I just started moving to WAB from flex, I forgot that for whatever reason when I add my layers to my maps that I going to be using on my WAB app I can only add from my secure GIS server making the app only https://. I see that your widgets live preview sites are not secure, I will have to investigate how to allow http:// sites also. My sites are public but they are only tests for now, interestingly enough I can get to my sites from my PC with only http:// i just get the message this is not a secure site.
The normal culprit for the required https when using WAB is that you entered a https url when you set the portal url when first setting up WAB Dev. If you go to the [instal dir]\server and delete the signininfo.json file and then restart WAB it will ask for the portal url again and this time use http not https.
Since you are just new to WAB, for other tips, news, training, and widgets, check out my blogs..starting with
A bit messy, but I update often. fwiw.