# Icon Workbench > A free, open-source app icon preview tool for iOS and Android. Try foreground and background images, preview circle and squircle crops, adjust blur, outlines and shadows, and zoom both layers together without losing their alignment. The corner-dot starter deliberately demonstrates circular cropping. Images are processed locally in the browser. No image uploads or account required. The editor supports PNG, JPEG and WebP. Download masked PNG previews and JSON settings. It does not generate artwork or produce complete native icon packages. Use current Chrome or Edge; download index.html to run the editor offline. - [Open the editor](https://lynxtwo.github.io/icon-workbench/) - [Guide](https://lynxtwo.github.io/icon-workbench/guide/index.md) - [Source and issues](https://github.com/LynxTWO/icon-workbench) - [MIT license](https://github.com/LynxTWO/icon-workbench/blob/main/LICENSE) Created by Daniel Boyd / LynxTWO. Apple and Android identify preview targets; no affiliation is implied.