This is an image editor for Apple II hi-res graphics. It operates on saved screens, which are about 8KB in size. The tool is written as a single-page web application, so you don't need to download anything to use it. It runs entirely in the local browser, with no server components or cookies.
You can launch the tool by going to https://hgrtool.art/, or (if domain names are being weird) https://fadden.github.io/HGRTool.
A brief demo video is also available.
This is not meant to be the future of graphics editing. This is primarily a vehicle for me to play with JavaScript+HTML+CSS.
The program was written in JavaScript, HTML, and CSS. It was developed with VSCode and the Chrome browser.
The source code is licensed under Apache 2.0 (http://www.apache.org/licenses/LICENSE-2.0), which makes it free for use in both open-source programs and closed-source commercial software. The license terms are similar to BSD or MIT, but with some additional constraints on patent licensing. (This is the same license Google uses for the Android Open Source Project.)
Images and documentation are licensed under Creative Commons ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/).