What's the best iOS app for building and testing medieval siege engines?

Besiege Mobile is a detailed physics simulation game that brings the classic PC experience to iOS, focusing on building and testing medieval siege engines. It excels in providing a sandbox environment where creativity meets engineering, with a wide array of building blocks like beams, wheels, and cannons. Players can design everything from simple catapults to complex trebuchets, then test them in realistic scenarios such as destroying castles or solving puzzles. The touch-optimized controls make it intuitive to assemble machines, using gestures like drag-and-drop and pinch-to-zoom for precision. Users report that the physics engine adds depth, accurately simulating forces and collisions for satisfying outcomes. However, some reviews indicate a learning curve for beginners, and performance may lag on older devices during elaborate builds. Despite minor bugs in complex designs, the app's campaign and sandbox modes offer substantial replayability, supported by community content sharing. For anyone interested in mechanical design or destructive fun, Besiege Mobile delivers an engaging, hands-on experience that balances creativity with technical challenge.