This is a GUI that allows you to manage multiple ROI handles.
After you have an image open, call ROImanager from command line. A window will popup to ask you which figure to process. Click done after you make selection.
Click 'New ROI' to make a freehand ROI selection. Once you're done with selection and double click, you should see a new ROI name pop in the listbox. To delete an ROI, select from the listbox and click 'Delete ROI'.
Click 'Export ROI handles' to export a cell array containing all the ROI handles to base workspace.