Also check stack overflow, github, SourceForge, etc.
Tutorials tend to be limited to small snippets of code to show you how to complete a single task.
I could pretty easily put together a tutorial that would show how to combine several images onto a larger "canvas" but it would be a low-level tutorial on how to create a graphics context and draw images into it. I would not include all the UI you would need for a collage app like selecting images from the camera roll, letting the user drag around the images before he generated the collage, displaying previews, a UI for saving/printing the output, etc.
Creating a full featured application ends up being pretty involved.
Thanks mate - I have been searching it on the web endlessly and I could not find any tutorials but I will definitely check out the links you have just given me. Also I wouldn't want to waste your time doing a tutorial just for me but thanks though. Appreciate the advice