I think it will be very useful to have the variable list as a window and not as a modal.
This way can :
- have the variable list side by side with app devel page to easily create / review variables.
- make use of full real estate of the screen, less scrolling up and down.
- Use the CTRL+TAB (in MS windows) to change between windows to quickly navigate between devel and variable list.
- maybe another future feature — to drag and drop variables in to widgets and triggers, instead of scrolling through a list.