I am new to the coding world. And when I say new I mean I am just now taking classes. However I have been in the GIS game for a number of years. I am trying to build a native application with AppStudio but I am running into a snag. My app is simple enough. I just want to display a feature service with popups, but also I need it to have the ability to add data (zipped shapefile, KML or KMZ, etc.) so the user can overlay their data on top of the background data I am providing. I can do this all day long with the web app builder, but is there a tool or widget I can customize the Map Viewer template with or possibly another route? Thank you.