Kirakira Camera Free app for iPhone and iPad

This is the free version
Paid version is here.
https://itunes.apple.com/us/app/kirakira-camera/id506185375

Resolution can not be selected free version.
Only 640*480.

It automatically identifies the shiny areas of a photo, and allows you to apply an effect like an SLR cameras cross screen filter easily.

You can choose from a variety of lights, and make heart or star-shaped sparkles.
You can also adjust the size and angle of the sparkles.
You can increase or decrease the number of sparkles.
You can choose a picture from an album or take one on the spot.

The effect shows up better in photos with a dark background like night scenes, and is less effective in bright photos or photos with no shiny parts.