John

Results 4 issues of John

### Pre-flight checklist - [x] I have read the [contribution documentation](https://github.com/electron/forge/blob/main/CONTRIBUTING.md) for this project. - [x] I agree to follow the [code of conduct](https://github.com/electron/electron/blob/main/CODE_OF_CONDUCT.md) that this project uses. - [x]...

Added Calcmatic as a new tool for ecommerce profit calculations.

Added a new section for tools with a link to Calcmatic.

Added Calcmatic calculator link to the README.