Add CertSync to your home screen.

CertSync is a Progressive Web App (PWA): it installs from certsync.co.uk and runs inside your browser with the same permissions as the website, not as separately downloaded software. Installing adds an app icon and stores the app's own files on the device so it opens quickly. When you work offline, your drafts, recent certificates and photos are also kept in the browser's storage on this device, and they sync to your CertSync account when you are back online. Photos taken without a signal are held encrypted on the device until they upload.

Very little for the app itself — typically just a few MB for the interface and icons, since PWAs share resources with your browser rather than bundling their own copy. Using CertSync offline adds more on top of that: your cached drafts, completed certificates and photos are stored locally too. Certificates and their photos share a 1 GB allowance on the device. If it fills up, the certificate you opened longest ago is moved off the device and shown with a cloud icon — it is still safe in your account, and downloads again the next time you have a connection.

On iOS: Press and hold the CertSync icon on your home screen, then tap "Remove App" or the minus sign. On Android: Press and hold the icon, then drag to "Uninstall" or tap "Uninstall". On desktop: Right-click the app and select "Uninstall" or remove it from your apps list.

Yes. PWAs update automatically when you open them. You always get the latest version without needing to manually update. You may occasionally see a brief "Update available" notification.

On iOS, you must use Safari - Chrome and other browsers do not show this option. On Android, try refreshing the page or check for an "Install" popup banner at the bottom of the screen. On desktop, look for an install icon in the address bar or check the browser menu.

Yes — the app works offline like it does online. Your dashboard, drafts, certificate lists and customers all open without signal, you can create new certificates and resume editing existing drafts, and completed certificates can be viewed as PDFs (the exact signed copy, where it has been opened online before and is still held on the device). Around 50 recent certificates are kept on the device automatically, and a signed certificate you open while online can be pinned to keep it available offline — a pinned certificate is never moved off to free up space. Certificates and their photos share a 1 GB allowance on the device. If it fills up, the certificate you opened longest ago is moved off the device and shown with a cloud icon — it is still safe in your account, and downloads again the next time you have a connection. Everything you do without signal saves locally and syncs to the cloud when you reconnect. Photos you take without a signal are held encrypted on the device and upload when you reconnect; signing, approving and sending a certificate are completed once you are back on signal. See certsync.co.uk/offline for the full list.

CertSync installs directly from the website rather than from an app store. Once installed it opens in its own window from a home-screen or desktop icon, updates itself when you open it, and runs on any phone, tablet or computer with a current browser. Because it runs on your browser's engine, a few device features open to app-store apps are not available to it, and some behaviour can differ slightly between browsers.