Been researching it for a couple of days, and it seems quite impossible (though highly desired).
I'm Looking for a way to anonymously identify users on our website as they later on run our mobile apps (both iphone and android, actually). At the very basic level, I'd simply generate a UID when someone visits our site, plant a cookie on their device, and then retrieve it later when our app is run. This simple implementation seems to be impossible, because the apps don't get access to the same cookie-base as the browsers (which makes sense, privacy-wise).
Also thought about using HTML5 for this purpose, which doesn't seem to provide any solution.
I Tried going the other way around and using the device id as identifier. However, seems like device id won't be available to the web server when someone visits our site.
There seems to be a perfect disconnect between data accessible from the browser, and accessible from the device itself in native apps.
Has anyone ever found a solution for this scenario?