The best alternatives to Dubble Studio are Dubble, 2by2, and Double Exposure for iPhone. If these 3 options don't work for you, we've listed a few more alternatives below.
What do you think of Dubble Studio?
Agree.com— The Best E-Signature Tool for Getting Paid (Fast)
dubble is a creative photo application enabling users to mix their photo with other people around the world. Often creating stunning, serendipitous double exposures