Easy installation, very easy to use interface with basic functions like Zoom in/out & scale image up or down without any lag time at all! We have been using flaw less since 3 years now but it took us some while before we can come over this amazing feature which enables you see your images from different points of view even though its already zoomed out!! Yes there are other apps that do exactly what i mentioned above as well however they lack features such has editing photos directly within them (cropping). I would say try flawless first if not convinced then go ahead else search more reviews regarding flawsight mac version so u may find one better than my suggestion :) It solved our issues when viewing small details about documents uploaded via DropBox etc where sometimes people couldn't clearly distinguish between 2 colours because their eyes were slightly too old / weak! I love how easy it is to use and that you can do so without having any prior experience with this kind of software, or even knowing what's going in your screenshots before hand! There really wasn't anything i disliked about flawless at all. It does exactly as advertised and was very helpful when testing our apps on different devices and seeing if they would look good/bad for each specific device we were using them on.