Android app PDF viewer & download service - LoGICBuGG

I have an android database app which needs to be able to view and download PDF manuals from the internet. The manuals need to be saved onto the device or an SD card in the device, the filename of the PDF will need to change, as one of the views used in the app looks for a specific filename to perform a function. Also depending on which button a user clicks on in the previous view will depend on which PDF is downloaded and saved, Most are manuals, however some are quick start guides and as such need the file names to be saved to show which is which.