Add to version control file, .gitignore. Include all instances of, .DS_Store, from Mac OS X.
Keep it simple, stupid! Move all class models to one file.
Add docstring for each class model, and reorganise reference to Entry class.
Reorganise class models, and rename Exercise class.
Update project settings.py file to reflect removed apps.
Restore order of class models. This is a scripting language. Also, add migration for new class structure.