In previous versions (2.4 and below) of Web App Builder Developers Edition you were able to overide the Corner Loading Gif in the bottom right hand corner through modifying the map .load-container in the jimu.js\css code.
Does anyone know how to do this in recent version of Web App Builder?
Thanks
Steven
In the current version the loading icon is a css animated div and is not something you can edit easily. You might be better off using the Map Progress widget that will disable the default loading indicator and adds a new one you can configure to your own gif.