A couple more things. The Desktop Web Viewer shows only published
content, not preflight content. To view your content in web viewer, you
need to publish it. See Publishing content for AEM Mobile apps.In your
screen shot, you're trying to sign an app, which isn't necessary at this
stage. Instead, you can use the preflight app. See Use the AEM Preflight
app to view AEM Mobile content. When you're ready to build the app, see
this article: Build AEM Mobile apps for iOS devices