UX tools and interface drawing tools for designers
MockFlow allows you to draw interfaces for your programs. It has a number of UI packs already installed, but the best ones are for the iOS. There is a very basic version that you may use for free without any sort of time limit. The two alternative subscriptions are paid, but they offer far more and are suitable for app or software development where there is more than one developer. Most of the design tools are intuitive because they are similar to drag-and-drop website design tools.
