Refactored the app so it uses the document architecture. You save a project file that persists the video you have loaded, and all the effects you have added. (You might need to do a 'New Document' when you first start, couldn't figure out how to have it auto start with an empty document). Should launch/load just by double clicking the project file in the future.
Also, added functionality to look in the Caches folder for previously extracted frames and previously processed frames, so that combined with the project file should allow you to restart a long render if it should get a crash (like due to memory issues).