[iPhone God App] It was found using the PhotoCalc actually

PhotoCalc is a utility for iPhone and iPod for photographers to calculate exposure reciprocation, depth of field, and flash exposure.

PhotoCalc offers handy calculations for professional or hobbyist photographers working in the studio or in the field. PhotoCalc provides exposure reciprocation, depth of field and hyper-focal distance calculations, and flash exposure calculations.

In addition to the calculators, PhotoCalc features a reference section with a glossary, and several reference documents such as the Zone System, and the Sunny 16 Rule.

PhotoCalc's reference section also contains an integrated version of Sunrise, a sunrise/sunset calculator that uses iPhone's ability to determine your location to accurately calculate the time of sunrise, sunset and solar noon for the current day, or any day you select.

PhotoCalc remembers the last position and values used, so it's easy to switch to another application or take a phone call and return to the exact same position.

PhotoCalc's features include:
- Exposure Reciprocation calculator
- Depth of Field and Hyper-focal Distance calculator
- Flash Exposure calculator
- Integrated version of Sunrise, a sunrise/sunset/solar noon calculator with a worldwide database of locations
- Reference section with glossary, and reference documents
- Configurable to English or Metric units
- Configurable to use half or third stops
- Comprehensive camera database for Depth of Field calculations
- Saves position, so it's easy to switch in and out

(Please note: version 1.2.1 of PhotoCalc is required for compatibility with Apple's OS 2.2.1 update!)