AppMaker lets you create an App which gets most of its content directly from you existing web site.
You take pages from you web site, assign menu labels to them, and then display those pages in the App.
It sounds easy and it is.
Just select the pages from you website which you want to feature, assign a label to each, and you are done.
But the App you create is much more powerful than just a collection of web pages because clients who download the App are encouraged to let you send them notifications of Specials, Sales and Events. Then they get a shake or beep on their phone are are notified right away so they can take advantage of your specials.
You can either encourage, or require your clients who download the App to give you their email address, so you can communicate with them using newsletters, etc.