Yes! We have an official desktop GUI for macOS, Windows, and Linux built with Tauri 2 and Svelte 5 (with native dark mode, visual diff, and a visual pipeline builder). We also have the full browser-based GUI running client-side via WASM at https://usepaperpilot.com/

FYI the box with the tool you've selected (where you upload and set parameters) is way too small on mobile. By scrolling you can use it, but you can only see a tiny bit of the interface at a time. Firefox on Android.

Both are actually already supported! We have pdf_decrypt (which unlocks password-protected PDFs given the password) and pdf_sign for applying cryptographic signatures, as well as pdf_validate_signatures for verifying certificates.