I miss the Mouseless RPN calculator on Firefox, so this is a welcome addition to my browser. The keyboard shortcuts are different, so will have to learn those. I do have some requests for the developer:

- Improve the number display, perhaps larger numbers with an easy to read font.
- Make all controls keyboard shortcuts.
- Allow user to set number format.
- Add financial calculations like time value of money and so forth.
- Make shortcuts identical to the Mouseless RPN calculator.