From the main website, click on Try it For Free button and start writing your App information, you will get a trial account for 14 days and you through this time you can test the service and see your App live using your generated QR-Code.
After you get an account either a trial or a purchased one, you can login into your App manager dashboard and add categories and items too.
From the App manager dashboard, you can see a list of items and near each item there is a delete button, by clicking on the delete button the item or the category will be removed and disapeared from your live App directly.
From the App manager dashboard and during adding an item, you can upload an image which will be your item attached image, and if you would like to change the image you can click on item edit button, choose another image and save the item again.
From the App manager dashboard you can change the App colors, logo and some other configuration.