It's very powerfull tool, this will allow to developers and users be more productive.
Enable feature in system:
To enable this feature you have to activate it in UDO's, you can see this official document.
Go to Security Workbench P00950 -> Form -> Feature Security, find "PERSFORM" and enable access:
Later you go to UDO's page and enable for users:
In P00950 -> Form -> User Defined Object -> Action. Click in Add: Fill fields
Works with Personal Forms:
In any form, you can see Personal Form icon on top right:
Click and you can start to personalize your form:
If you click on less icon, the field hided and it'll appear in right panel for if you want show later. you can move fields, resize, change labels, etc.
For more information you can access this official document.