What is a Crypto Wallet integration API?

Could you elaborate on what a Crypto Wallet integration API is and its significance in the cryptocurrency and finance landscape? I'm curious to understand how it enables seamless integration between various crypto wallets and financial applications. Specifically, I'd like to know about its key features, benefits for both wallet providers and application developers, and any potential challenges or limitations in its implementation. Additionally, I'm interested in exploring real-world examples of successful integrations utilizing Crypto Wallet APIs.