This webpage from Envato Tuts+ provides a set of tutorials and resources to build a photo app using GPUImage. The platform offers comprehensive learning materials covering several topics including WordPress, HTML/CSS, Mobile Development, JavaScript, PHP, Python, Ruby, and Cloud & Hosting. The page features subcategories in each of these areas and encourages the user to start learning about each topic.
Build a Photo App with GPUImage
http://mobile.tutsplus.com/tutorials/iphone/applying-image-filters-with-gpuimage/