However only the "Gallery" has the ability to crop.
Only on some devices. There is no requirement, AFAIK, for a gallery app to offer some sort of cropping capability.
So I need a way to filter the other three apps
No, you need to realize that there is no cropping ability that is officially part of Android. Then, you need to implement cropping inside of your app. This is covered in greater detail in a blog post of mine that baronS mentioned in a comment.