Poorly designed
I tested this app on a half dozen different PDF files (all text). In only one case did the app manage to reduce the file size (by about 80%) and keep the text legible. In all other cases, it either rendered the text completely illegible or it actually *increased* the file size. What is worse, the program first runs through the whole process of compression (which can take several minutes with large files (ca. 50MB)), and only then tells you that it could not reduce the file size because the file is already compressed. Also, there is no way of stopping a compression process short of quitting the app. $2 wasted.
Leser in den USA about Compress PDF