Apple iTunes has a free iTunes App Sale: Shoot by ProCam (normally $1.99).

About

Shoot by ProCam is a powerful manual camera designed with the photography purist in mind. Shoot offers a distilled camera experience through a streamlined UI, pro specs, and blazing fast performance. If you're looking for the best manual camera controls and the highest photo quality, then Shoot is the app for you.

Requirements

• Requires iOS 8.0 or later
• Compatible with iPhone, iPad, and iPod touch