NDcam lets you create long exposure and multiple exposure images by taking consecutive pictures for a period of time and then processing them into one, the results are amazing!
Filter Options:
- Dark Pass great for backlighting, sunsets, taking pictures at birds, see the examples.
- High Pass great for light painting and sunsets.
Misc:
- See in real time how the picture is turning out.
- It has a 10 second timer, just in case you want to be in the picture :D
- And you can press stop at anytime if you wish.
It is so simple to use, use the app, experiment with the options and see the screenshots to get some ideas ^_^