Without using any other Apps at all students have the opportunity to document their work by photo, reflect on their work by videoing themselves responding. They can also edit their photos to focus or zoom in on an aspect. They can create folders of photos to organise their work and then create slideshows that they could Airplay in class.
A little known function is the ability to reorganise your photos in a folder in your Camera Roll so that students can arrange the slideshow of photos in the order that they want. In a photo folder you select 'Edit' then touch/hold photos till they become moveable and then you can rearrange them in your album .
Use the camera feature to get students to see the Maths shapes and concepts in the world around them and talk about it. Take a photo of a book cover or page, airplay it and then respond in class orally to the images.
A useful resource for ways to use the camera in learning is:
10 ways to use your iPad camera in the classroom