Can my customer keep their existing website?

Yes, your client can keep their existing website and use their StickyApps site as mobile friendly option or focus on the App like aspects of the StickyApp.

To do this you would not use the root - or main url. Example: mysite.com

You would want to create a sub-domain for your StickyApp site.  Example: app.mysite.com or mobile.mysite.com

Setting up a Sub-Domain A Record

To create a sub-domain and point that back to our sever:

1. Login to your DNS provider

2. Create a sub-domain example: apps or mobile 

3. Select A Record as the record type for your Sub-domain

4. point the A Recrod to our IP 54.244.117.9