How does a tested Crypto Wallet work?

Could you elaborate on the functionality of a thoroughly tested crypto wallet? I'm curious about the security measures it employs to safeguard user funds, the user-friendliness of its interface, and how it handles transactions. Does it support multiple cryptocurrencies? What about its storage options? Is it available on various platforms? And how does it ensure the privacy of its users' transactions? Understanding the workings of a tested crypto wallet is crucial for any investor seeking to safely store and transact digital assets.