When it comes to PDF processing, there is a large pool of software available for this purpose. However, with so many tools developed for this, one might be wondering which is the perfect one for them. Personal preferences, popularity, ease-of-use, and others, might constitute reasons for someone to pick such an app. First things first - when you open the app, you'll notice that the tools are centered on the UI, much like a calendar. The point of view can be changed by clicking on any feature.