Write an Android application

Hello, I would like to hire a developer to help me design a simple Android wallpaper app. The app should: -Be in gridview -Allow myself to host pictures on server -Able to add new pictures or remove pictures from the server, and the changes will be seen in the app itself without updating the app -A tutorial to guide me on how to host the pictures (lol) -Able to save images to SD card -Have a smart banner ads template at the main and Wallpaper Preview page and an interstitial ads when "Set wallpaper" is pressed. (just the template for google admob ads will do, and I will change the ID myself) -At the wallpaper preview page, cropping option is available for user to crop their desire size -Able to set wallpaper as lock-screen. -Able to favorite an image, and have a separate "Favorites" sections displaying pictures which the user have "liked". -Support multiple devices, i.e. the grid size should change according to the device size, and the pictures in the grid should not be too small for bigger screen -When one of the picture in the gridview in the main page is selected, a download window should appear to allow the user to know that an image is downloading (something like Asynctask) -The app should be able to read the wallpaper from cache after the image is downloaded from web (which means no waiting time when the user click on the same picture again) - A finished apk with sourcecode In short, the app should have similar function to this (pls do not design it to be exactly the same) [login to view URL] I do not need the following: -Share wallpapers to social media -Splash screen -Live wallpaper I gave up coding the app myself from scratch, as I have no knowledge on how to host the wallpapers online and subsequently able to add more wallpapers for the user without having to update the app. (you would have to tell me how...) A full source code is expected on delivery ;) Do quote me a price, and the time needed. ;) (Honestly I am not sure how much should I pay for it. Of course the lower the better, as this is not a very complicated app. I am looking at 3 digits pricing) thankyou