Found this webpage Smith Chart tool/calculator (not mine), and liked it a lot, for being very clean and easy to use:
https://www.will-kelsey.com/smith_chart/ The webpage works offline, too, when saved locally, thank you Will Kelsey (the author, I think).
When offline the webpage needs one more folder that is not automatically saved at the "Save as" webpage. The missing folder is called "icons" (or else the networks icons will be missing). The folder icons needs to be placed at the same level with the "Smith Chart Tool.html" file, then open the saved .html and use it like it would be an online page. The missing icons files can either be saved one by one as .png files inside the folder named icons, or just unzip the 'icons' attached folder. All copyrights, if any, belong to their authors.