Launch program. You will see the following window.
Press button to open a standard File Open Dialog.
Select folder containing photos to shrink and press "Open".
The selected folder and the first photo will be indicated on the program panels.
Press button to start shrinking.
A progress bar indicates status of process.
You will see the following window when done.
The "Result folder" label indicates location of folder which contains a set of shrinked files.
Press button to exit program.