Ability to use left or right Shift, Control, Alt/Option, Command on Mac

I'd like to be able to choose which side (left or right) of the shift, control, alt/option, and command buttons to use as shortcuts. When I setup the keyboard shortcuts, I would like to use SHIFT and any buttons on the keyboard (number or letters) for snapping. However, if I use SHIFT the letters that I use cannot be used to capitalize the letters anymore. For example, if I use "SHIFT + a" to snap left, I can't use my right SHIFT to do capitalize that letter "a". So with this feature I would be able to use my LEFT SHIFT for the keyboard shortcuts, while leaving the RIGHT SHIFT for capping the letters.

Before entering the shortcut, press the settings/gear icon to bring up the options and select "Differentiate between left and right modifier keys"
Save it and enter the shortcut

Will have an "r" or an "l" next to the shortcut in the list to show it worked.

Oh man, I have been using bettersnaptool to do this. I totally forgot about the bettertouchtool. I just tried it and it works! Thanks!