Add Watermark on Facebook profile image with an APP

Could you please help me with the app that you have made to add a watermark to the people that give authorization to it. I have been searching for that app and i have not found anything neither info about the code to get it. Could yo help me please with this or tell me important i开发者_Python百科nformation to success in my intention. Thanks and best regards

As far as I know, you can't alter the profile image itself. You can retrieve it, upload the to profile album but you can't set a profile picture.