Download of Pict2Curl 2.1 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This Mac application is a product of Tomoyuki Okawa. The program lies within Design & Photo Tools, more precisely Viewers & Editors. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
Pict2Curl combines a pair of pictures curling one of them over the other. The result can then be saved as one image. You just need to select a top picture and a background picture separately, using OpenPanel or drop box. Next you determine the peel position, manage the degree by which the top picture will be curled, and select a picture as a background shade image or a solid color as background.
You may want to check out more software for Mac, such as Cuadro or Resize Now, which might be similar to Pict2Curl.