Android App - Photo Viewer - Repost

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: Features: The main functionality is : the app displays a random photo loaded from our server from a set of categories selected by the user, when the user taps the screen, the next photo is shown, we don't want the user to wait for each photo, so the app should fetch every 10 photos together and save them to the device (showing a progress bar with the number of photos loaded, (Loading 1/10..etc)), when the number of fetched photos reaches 50, the app should delete them from the device so that they don't occupy too much space. So basically here's how it goes: application start -> category selection (when the app starts - opening screenshot provided by us) -> fetch 10 random photos from the server based on the users selection of categories -> when user reaches photo number 10 fetch the next 10 random photos, when the number of fetched photos reaches 50, the app deletes them from the device so that it doesn't take too much space, then the same process starts again. 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. The server will be updated with photos daily, so the app should detect any new photo when it is uploaded to the server (on a daily basis). Interface: *the photo should occupy the entire screen, no buttons shown except a small back button (a transparent arrow) at the bottom left of the screen that takes the user to the previous photo. *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 one select all tick ehich activates all categories, and a button which says "Go!" (opening screenshot provided by us). *The back button on the phone takes the user back to the main menu (category selection). Menu button: the menu button should contain the following: [login to view URL] as Background: the app sets the current displayed photo as a home screen background exactly as it looks inside the app. [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(opening screenshot also provided for the free version). *The four menu options are also shown upon clicking the menu button on the phone but disabled as well. *The number of photos to be shown is limited to 20 photos per day (the app will fetch 20 photos in this case, 10 at a time), after the 20th photo a screen with two buttons is displayed, it should say "This version is limited to 20 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 same 20 photos which were displayed before), and "Take Me There!" (opens the play store for the full version). *A fifth button is added to the Menu which says "Buy Full Version!" and takes the user to the full version at the play store. Please read the features carefully and bid accordingly.