FREE: Holographium - Light Painting App for Photographers - iOS (iPhone & iPad) - Was $6.49

According to AppShopper it has not been free since Jan 2013.

Description copied from the App Store:

Meet Holographium, the next-generation light painting machine with a twist!
Holographium slices text or images into thousands of luminous 3D cross section scans, and projects them over time on a long exposure photograph.

The result is mind-blowing: Your digital camera captures a glowing, hovering "hologram" with real-world reflections!
Check out holographium.com for a demo video and examples!

Holographium is ideal for anyone interested in light painting.

Note: It requires an additional digital camera. It works great with cameras from Canon, Sony, Nikon or any other brand.
Before you buy, please make sure you can take long exposure photographs of at least 3 seconds.

~ Features ~

✓ Choose between Text / Graphics Mode.

Graphics Mode:
✓ Extrude any graphics you like: Logos, icons and even photographs! Holographium reads many file formats: PNG, BMP, JPG, GIF and others.
✓ Import from Photo Albums, Camera Roll, Camera or iTunes File Sharing.
✓ Awesome graphics included to start quickly.

Text Mode:
✓ Type in any text you like.
✓ Renders almost any Unicode symbol!
✓ Select one of 9 carefully chosen, beautiful colors.

The most advanced Taptanium User Interface:
✓ Polished high-quality audiovisual user interface.

High-Performance 3D Light Painting Engine:
✓ Hardware-accelerated high-performance rendering.

3D Light Painting Settings:
✓ Set a countdown between 0 and 30 seconds in 1-second steps.
✓ Set the duration between 3 and 30 seconds in 0.5-second steps.
✓ Set the depth (thickness) of your 3D light paintings.

And Many More Features:
✓ Approximated 3D extrusion preview.
✓ Calculates the extrusion distance in inch or cm.
✓ One-second interval sounds and 50%-done sounds (optional).
✓ Adjust the screen brightness in Holographium (iOS 5+).

~ Instructions & Help included ~

✓ Cool 3D-animated demo video included.
✓ Beautiful step-by-step guide included.
✓ Many tips included!
✓ Frequently Asked Questions (FAQ) included.
✓ Displays contextual information.
✓ Contact Support feature included.
✓ Smart & beautiful annotations introduce the interface.