This is a paid asset, but now you can download Gesture Recognizer Free.
Detail this asset from Unity Store: Original Link
Gesture Recognizer v2.4 (Latest version)
Gesture Recognizer is powerful, easy to use, gesture recognizer for touch or mouse input. It recognizes the drawing made by the player.
You can set your own gestures patterns to be recognized.
Main features:
-Create your own gestures
-Gesture made of one or more lines
-Support closed shapes like circles, squares, triangles
-The gesture can be draw in in any place of a free area, or in the exactly place in a fixed area (good for kanji among others)
-Recognition runs in another thread to avoid framerate drop
-Option to use or not the order of the lines of a gesture
-Option to use or not the line direction