PHsPeed is great for your prototyping projects and is suitable for your agile approach. Design together with your (end) user or create your prototype without any code needed.
Select a database table, select an application type and click the fast generate button. That's the fastest way to an application. Back in the IDE you can pick it up and modify it to your needs. If you are a developer you can follow the steps and set preferences for the generation process.
The IDE shows a conceptual design of the form. Conceptual as in Bootstrap the layout depends on the device the form is displayed on.
Change colours, buttons, themes by simply changing properties.