integrate paypal payment in app

I have already a project that is a photo gallery . i will pay $25 . what i want to implment is just paypal payment for people to view gallery . i want you to have java file for constants for the price and the email that payment will be sent to . USE PAYPAL MPL REST API this should be for people who already integrate paypal payment before . ow in json , i add category type which will have one of this values ( free - paid ) so if he click a free category , every thing will work as its without request for any payment . but if he click paid , we will check if user subscribe with this url : [login to view URL] if he is , then he can view the content and all paid categories . if he is not then it will pop up him a message that he need to subscribe to this app to view this content and show him the payment button . after user do the payment and the payment is success , we do this request : [login to view URL] ================================================ THE PAID CONTENT WAYS OF BROWSING ========================================================= the browse for photos already have been made . you just need just to add this tiny thing now after display categories and user click category , and access it . and we display pics under the category tin current app he normal thing that when we click picture , we display it in full size . with the footer we display 2 arrows for the next photo and for the previous photo . ONE EXTRA BUTTON WILL MAY DISPLAY BASED ON JSON . now once the user browse pics , in json there is a field called ( d_url ) d_url = url for download . if its not empty we will display button for download , otherwise we do not display the button . once user clicked it , it will ask him where to save the downloads , and then after confirm location , it will start and save the download . also fix the depcrated codes . this should be made in one day . to make me award you , you need to prove that you understand what i want and you can do it . you have already work with paypal for android . send me apk proof you understand and example .. this is the source code that i have and that already been made . you need to proof me you understand how the code work [login to view URL] i will sleep and get back after about nine hours , any one fulfill the project in this nine hours will be paid . any bid above $25 will be ignored