Develop a downloadable Android and iOS app to launch a mobile friendly web site.

I have developed a mobile friendly web site which allows a customer to log in and order products.

Once customers are logged in, I would like them to be able to download a link or app for either Android or IOS that places an icon or launcher on their phone or tablet's home screen. When the the customer taps the icon it will launch the web site, I don't mind whether this happens in app webview, or simply opens the site in the device's default browser.

Ideally, I would like the "launcher" to log the customer into the website automatically after the first use. I'm not sure how to achieve this. Each download could be personalised, such that the log in information is stored as an encrypted string and it links to a "receiving page" where I decrypt the string and log them in. Alternatively, perhaps, we use the same app for everyone which would then require the customer to log in the first time they use it, store that information locally on their mobile device and thereafter log them in automatically.

If this sound like something you could help with, please get in touch.