Editing a photo I have not taken from their app is one of the reasons I enjoy using this because I can always change the effect whatever is my fancy.
If however, you use this app for taking photos, it keeps the original photo + the one with that effect you have chosen beforehand, none of that in other apps. I love this feature too because I would at least have the freedom to choose the best effect later on.
They also have quick frame collages which has a timer that allows you to take a sequence of photos like as if you are in a photo booth. Their beauty feature also works as a charm, I have already used it to recognize my face and slim it!
Below is a good example of their filter:
Note: Collage was created through KD Collage because I was secretly taking a photo of my friend in random