Numi App - Numi is a beautiful text calculator for Mac.
Soulver - Soulver is a software application that functions as a calculator that allows you type a continuous stream of information rather than having to input data into multiple cells.
Observable - Interactive code examples/posts
SymCalc - Symbolic Calculator - Math toolbox for iOS. Advanced calculator features with a tape-like history, not requiring internet...
nbviewer.org - Rackspace server host Jupyter Notebooks from your github repo
Parsify Desktop - Extendable calculator for the 21st century ⚡