Besides a program, UI Drafter is a technique for brainstorming apps without graphic design overhead. This way you can figure out the essential content and its flow in total focus.
For example, unlike wireframing, there's no need to keep track of screen sizes and layout constraints. Therefore, you can devise, organize, and try ideas faster and with more mental room.
UI Drafter lets you take out of the equation the unnatural awareness, imagination, and memorization needed to evaluate mockups. In effect, giving you more confidence on the accuracy of the usability tests and their feedback.
Also, it helps you prevent rework by discovering blind spots and missing pieces before building. In other words, now you can communicate what you're trying to achieve in more tangible and functional prototypes.
Try out page flows, groupings, and progression alternatives.
Experiment with different labels and UX writing practices.
Discover edge cases early on.
Convey complex requirements in a tangible live spec prototype.
Make the graphic design phase feel more familiar and direct.
Enter and stay in focus easier.