Application refresh and new Folders feature

I modernized the technology stack by rebuilding the front-end in React and upgrading the back-end from Python 2.7 to Python 3.6. This upgrade will make it easier for me to continue to build upon SnipSave and add new features and functionality.

I also built a new organizational feature: Folders. You can now create custom folders and drag code snippets into them for quick organization.

Search and filtering speed has been dramatically improved as well.