Recompress

Re/compress is a simple application designed to help you compress large-sized PDF files. This way, you can save valuable space on your disk and optimize your documents for e-mail and web sharing.
The tool has a Dock icon appearance and installs in the upper bar of your Mac.

Without the presence of a user interface, compressing files is done either by dragging and dropping your PDF into the Dock icon or by enabling the 'Open file' operation from the menu bar. Consequently, the compression starts automatically, without any other manual intervention. All you can do is look at the compression progress bar and wait for the process to end. Then, you may play detective to find the compressed file, since you have no clue where it was saved. The program neither asks for a destination folder nor informs you about an already-defined path. The only options available are to be found in Preferences, where you can set the compression quality by dragging a slider, choose the output resolution and select the compression level. Optionally, you can rasterize the pages to bitmap graphics.

With a straightforward compression approach, the application is easy to use. Yet, you may dislike the absence of an interface and the trouble of searching your entire computer for the compressed file.