While plug-ins and external editors require a client application such as Aperture or Photoshop, the standalone application can directly process JPEG or TIFF files.
To install the standalone application drag it to the Application icon in the DMG folder. This will place program PTLens.app in your Applications directory.
Process an Image
Double-click on the PTLens icon in the Applications directory. If the PTLens dialog doesn't appear perhaps you forgot to disable Gatekeeper. After the dialog opens choose the Directory button and navigate to a directory that contains JPEG or TIFF images. The files will be listed in the text box on the right. Select a file, make adjustments, and choose the Apply button. This will create a new file, with corrections, with a "_pt" suffix. For example, if the original file was abc.jpg, the new file will be named abc_pt.jpg.
For further information choose Help > PTLens Help. I suggest you spend five minutes and read the section titled Getting Started > Quick Start.