Executing shell commands, splitting notebook cells, collapsing heading, Qgrid (dynamic table as Excel), Slide shows (fixed, or interactive), embedding contents (url, pdf, youtube video, etc), or interactive widgets :

• https://towardsdatascience.com/bringing-the-best-out-of-jupyter-notebooks-for-data-science-f0871519ca29

Environment switching, plus a list of 9 useful extensions, but without examples:

• https://towardsdatascience.com/supercharging-jupyter-notebooks-e22f5ad7ca18

Profile report of a dataframe, interactive plot with plotly, and useful magic commands:

• https://www.kdnuggets.com/2019/07/10-simple-hacks-speed-data-analysis-python.html

Variable inspector, execute time, hide code input:

• https://towardsdatascience.com/jupyter-notebook-extensions-517fa69d2231

Notify, code folding, debug:

• https://ndres.me/post/best-jupyter-notebook-extensions/

Much more to explore here:

• https://github.com/markusschanta/awesome-jupyter

Qgrid demo and more:

• https://github.com/quantopian/qgrid

Unofficial Jupyter Notebook Extensions page:

• https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/