MengTo/Spring ? reverse-engineered prompt

Build me an iOS animation library in Swift that makes it really easy to add playful view animations to an app.

I want to be able to connect a UIView in Interface Builder to a custom Spring view class, set animation options in the inspector, and also trigger the same animations from code with simple calls like animate and animateTo. Please include a bunch of built in animation styles like shake, pop, morph, wobble, flip, slide, fade, zoom, and flash, plus curve options like spring, linear, ease in, and ease out.

It should support chaining animations, basic timing controls like duration, delay, damping, velocity, repeat count, scale, x, y, and rotate, and convenience features like autostart and autohide. Make it feel polished and easy to drop into an existing Xcode project. If you need to check current Swift or Xcode docs online, go ahead.