Android App - Photo Viewer

We need an android photo viewer, The photo viewer has two versions, free and paid, here's the general description which applies to both versions: The main functionality is simple, the app fetches a photo from a server which has a database of photos, when the user taps the screen, another randomly (not completely random, see below) selected photo from the database is shown, and so on. This database is divided into a number of categories (to be determined soon), the user selects the preferences on which category they want to see photos from. All the names and contents of the categories are provided by us and saved in the server which is also owned by us, each category is saved in a separate directory, however, linking the server to the mobile device is the developers job, and his advice on the indexing of the photos is welcomed. Interface: the photo should occupy the entire screen, no buttons shown except at the start of the app, when the app starts it should show a menu with the 5 categories with the option of selecting multiple categories (by ticking a box on the desired category) and a button which says "Go!", after making the selection the app should display a photo according to the categories the user has selected, when the user taps the screen, another photo that satisfies the same selection is shown, and so on. Menu button: the menu button should contain the following: [login to view URL] to Device: the app saves the current displayed photo to the sdcard. [login to view URL] Destination Folder: change the folder in which photos are saved (default is sdcard). [login to view URL]: this option allows the user to change the category from which photos are displayed. The restrictions to the free version are the following: *The categories selection at the start of the app is shown but disabled, only the "Go!" button is active. *The three preferences are also shown but disabled as well. *The number of photos to be shown is limited to 5 photos per day, after the 5th photo a screen with two buttons is displayed, it should say "This version is limited to five photos per day, purchase the full version for 2.49$ only for unlimited access to thousands of top quality photos!, as well as the ability to pick your favorite style!", the two buttons say: "No, Thanks!" (upon clicking on it, the app displays the first photo and displays the rest of the five photos when the user taps the screen again), and "Take Me There!" (opens the play store for the full version). *A fourth button is added to the Menu which says "Purchase Full Version!" and takes the user to the full version at the play store.