For every controller that is unique to the feature you're working on, place the controllers to the corresponding folders. i.e: Seller Edit for the Selling Tab (controller should be placed in Spotter/Controllers/Selling)
For everything else that is shared, just place it in Controllers.
For bridging files and the like, place it under Spotter/Supporting Libraries
For classes, PascalCase.
For variable names, camelCase.