As a developer, I have to click save application and wait, then click close application and wait, then click deploy and wait, then finally click lauch.
For larger applications, this may take minute or two. Please allow to do so in a single click of a "Save&Launch".
Remark: Preview is insufficient in many scenarios, for example:
once you need to save and deploy services
once you need to test action buttons
once you need to test forms/pages in various stages