I know this question has been a long time ago, but I just found a way to refresh the page automatically while any changes are made on the scripts.
Try the tool below and follow the instruction:
generator-esri-appbuilder-js
It can generate the template of a widget and you need to install "LiveReload" extension for Chrome.
Run "grunt" from command line.
The page will refresh when you make any changes on the project.
My description is a bit brief, following the link above I think you'll get it work.