What's the best iOS app for testing how a website looks on different screen sizes right from my iPad?

QXZJW is a mobile viewport simulator tailored for web developers and designers who need to verify responsive layouts on the go. The core functionality revolves around its ability to render websites within a resizable frame that mimics various screen dimensions, from smartphones to tablets and desktops. This is particularly useful for freelancers or agency workers who may need to perform quick checks during client meetings or while away from their primary workstation. The app includes a library of preset device profiles, such as iPhone 15 Pro or various iPad models, and allows for manual input of custom resolution and pixel density. One notable feature is the ability to toggle user agent strings, letting testers see how a site behaves when it identifies the request as coming from a specific browser or device. For a real-world scenario, a developer could use QXZJW to quickly confirm that a newly deployed CSS fix for mobile padding appears correctly across half a dozen common screen sizes before signing off on the update. Reviews indicate users appreciate the straightforward, no-fuss approach to a single task, though some note that the interface feels a bit dated compared to newer design tools. The lack of advanced debugging tools like element inspection means it is strictly a visual testing companion rather than a full development environment. Nevertheless, for its intended purpose of rapid, visual responsiveness checks, it remains a practical and focused solution.