Why these tools exist
Making a website into an app is mostly a series of small, fiddly requirements that the website never had: an icon at six sizes that survives a launcher mask, a package name Android will accept and you can never change, a version code that goes up on every build, a splash screen that respects Android 12's rules, permissions that match what your pages actually ask for, screenshots in the exact ratios Play allows. None of them is hard. All of them fail a build or a Play submission when they are wrong — usually after you have waited for the build to finish.
Every tool here does one of those jobs in the browser. Nothing is uploaded — images are resized with the Canvas API, ZIPs are packed locally, and the checkers never touch the network — so they work offline once loaded, and dropping your logo or your site's source into one of them sends it nowhere.
If you want the whole job done instead of the pieces, the free APK creator takes your site's URL, an HTML file or a ZIP and returns a signed Android app — it generates the icon set, the splash screen and the manifest for you. These tools are for seeing the pieces first, fixing a difficult logo, or checking a ZIP before you upload it.