To have four steps or screens, the first to select beer or lager etc, then to list a maximum of 8 suppliers such as Fosters, Becks, Carling, Carlsberg, Budweiser, Stella, Grolsch and Brahama, then from the www.mysupermarket.co.uk to show the options for that beer type (e.g. six pack, fridge pack, 4 pack as from the main panel here http://www.mysupermarket.co.uk/#/Shopping/FindProducts.aspx?Query=fosters) and when clicking on that type of pack it shows the prices at ASDA, Tesco, Ocado, Sainsburys and Waitrose, again from mysupermarket.co.uk.
The app needs writing for both Android & I-phone. If you are quoting just for one platform you need to say so.
See attached document...