What app makes faces blurry in pictures?

Many times you see pictures on Facebook or Instagram where the pictures are clear except for the faces which are blurred out. These blur edits look like fog or frosted glass effects over the faces so the faces are not recognizable, yet the rest of the picture remains clear. Often you see similiar photo edits where the entire background is blurred out and just the person or face in the center of the photo is clear, making it stand out more.

The app "FingerBlur" is shown in the screenshot below. This allows you to simply use your finger to wipe the areas you want to remain clear. You can adjust the blur level thicker or thinner, depending upon how clear or "see through" you want the blur edit to be. This can range from a slight blur to a thicker frosted glass edit, simply by tapping a button and wiping parts clear with your finger.