There are 3 scientific gems for Mac: Colocalizer Pro, Papers, and Macnification (in chronological order of their releases). All work and look great, use clever metaphors for icons, and created by the people who seem to know exactly what they are doing. Colocalizer Pro is designed for more a specialized type of image analysis, like quantification of colocalization, while Papers and Macnification are for more generally-oriented. I purchased Colocalizer license last year and already published a paper with its help! Thanks to support documentation, the learning time is short. Export results in Excel format is hard to beat too. I can highly recommend this application!