I am preparing to begin work on a project that will let you listen to your music collection from any device. My plan is to build it as a responsive website, so I can target pretty much every device with just one frontend.
The problem is that I want the app to work offline. I want users on both mobile and desktop to be able to save songs for offline play and I don't want the app to be strictly dependent on the presence of an internet connection.
Is this a feasible idea? I think I could probably make this work on the desktop end by adding a Chrome extension or app (I'm okay with my website being limited to just one browser), but I have no clue if this is doable on mobile. I only really care about Android; is there any way I can make this work on Android as a web app?
aside: Yes, I know that a web app will never be quite as user-friendly as a native app. I'm planning to do this project solo, so I care more about reducing development man-hours than about having the perfect UX.
TLDR: I'm making a responsive web app, but I want it to work offline on Android and on Chrome for desktop. It needs to be able to store lots of large files permanently and work without an internet connection. Are there any libraries/APIs/software that would allow me to do this?