Hello @MadeUpMasters
As far as I know, there’s no package that gathers every useful snippet made by the community (or even by Streamlit Team, like the ones you’ve posted 
). Feel free to make a real python package, some people will definitely find it useful!
Session state (and more precisely programmable state) actually is: Programmable State Survey! - Official Announcements - Streamlit
As for pagination/tabs, and other layout components, they’re “In design” apparently: Roadmap · streamlit/streamlit Wiki (github.com).