Best way to crop a square from a selected image in Android?

In the app I'm building the user is able to select an image from the gallery, and now I'm searching for a fast and simple way to crop a square (zoomable and draggable) from the selected image. All the solutions I have seen so far utilize the "com.android.camera.action.CROP" intent, which is not present in all phones and hence could cause a problem. What is the easiest way to implement this kind of cropping?