This repository contains an Android library for creating additive animations, where multiple animations can be combined by adding their values together rather than having later animations override earlier ones. The library provides a fluent API for animating View properties (position, size, rotation, alpha, etc.) and custom object properties. Key features include physics-based spring animations with configurable stiffness and damping, animation chaining with flexible timing controls, view visibility animations that automatically handle state transitions, and a sophisticated animation state system that determines whether to run animation start/end logic based on the current state of the target object. The implementation stands out for its physics-based spring solver (SpringSolver.kt) which provides an analytical solution to the damped harmonic oscillator equations, handling all damping regimes correctly. The RunningAnimationsManager provides intelligent state management for animations, eliminating common boilerplate for visibility and state-based animations. The library is actively maintained with recent updates, uses current AndroidX dependencies, and follows modern Android development practices with Kotlin coroutines and Java 17 compatibility.