Cordova is an open-source framework to convert Onsen UI apps to native webview-based apps running locally on iOS and Android. Onsen UI apps made using Cordova can be put on the app stores. Take a look at our Cordova guide to get started.
Progressive Web Apps (PWAs) brings a new experience to your mobile websites. A PWA is a website which is available offline, and can be added to a user’s home screen, just like an app. Take a look at What is a PWA? for an in-depth guide on PWAs. We also have a comprehensive Onsen UI PWA tutorial to help you use Onsen UI to create a great PWA.
Onsen UI is also suitable for developing web apps with any screen size. Onsen UI components are responsive and scalable, fitting perfectly even with desktop websites. Furthermore, you could create a desktop app by using Electron or Node WebKit.