Open the web app in Chrome or Edge. To install it as a desktop app: click the install icon in the address bar (or Menu → "Install Corp To Do"). It gets its own window, taskbar icon and notifications.
Open the web app in Chrome on your phone → tap the ⋮ menu → "Add to Home screen" / "Install app". Corp To Do installs like a normal app with its own icon and notifications.
Open the web app in Safari → tap the Share button → "Add to Home Screen". The app appears on your home screen and runs full-screen.
Native Android (Play Store) and iOS (App Store) builds are on the roadmap and will use the same account and backend — nothing to migrate.