Lightmate

Lightmate is a simple light meter app for photographers. The user interface is designed with clarity in mind.
Features:
• Aperture and shutter priority modes
• Multiple EV scales (iOS Settings > Lightmate)
• Back and front camera support
Instructions:
1. Choose the ISO, Aperture (or Shutter) values according to your camera settings.
2. The priority changes automatically to Aperture (or Shutter) mode when you change the Aperture (or Shutter) value.
3. Tap anywhere on the camera's preview screen to measure and update the exposure values.
You can switch the priority mode by just tapping on the Shutter or Aperture values.
Settings:
You can change the default EV scale individually for Aperture, Shutter Speed or ISO values.
1. Go to the general "iOS Settings"
2. Scroll down until you find "Lightmate"
3. Change to a different EV scale (full stops, 1/2 stops or 1/3 stops)