Add functions to PhoneGap app

Hi there, I have purchased the source code for a "Slider" app made with phonegap. I want to use this app to display a restaurant menu on my tablet. I already have it working and displaying the images of the food. What I need is 3 small functions to be added: 1- I want the first slider to act as an index for the app. This page will be divided into Menu Categories. "Starters", "Fish", "Meat", "Rice", "Desserts", "Drinks". etc. Each menu category will contain a list of menu dishes which if clicked will take the user to the respective slider with its photo. Shown below is an example using Meat category "MEAT" a) Pork in sauce b) Fillet Steak c) Roasted Chicken If the user clicks Fillet Steak, the app will take him to the slider with the image of the Fillet Steak. 2- Add a button on each slider called "Return Home", which will take the user back to the index slider. 3- On the index page I want two flags to appear (Spanish and English). This will offer the app in another language when clicked. I will supply all the text. Regards, Richard