Are there any dApps built on top of the network yet and if so what are they used for?
Yes, there are dApps built on top of the Polkadot network.
These dApps are used for a variety of purposes, including decentralized finance (DeFi), asset management, and gaming. One example of a DeFi application is Acala Network, which is a multi-chain DeFi platform that enables users to create and manage digital assets such as stablecoins, loans, and savings accounts. Acala Network is built on top of the Polkadot network and allows users to access its features without having to leave the Polkadot ecosystem.
Another example is ChainX, which is an asset management platform that allows users to securely store and trade digital assets such as cryptocurrencies. ChainX also provides users with access to advanced trading tools such as margin trading and derivatives trading. Finally, there are also gaming applications built on top of the Polkadot network.
One example is Splinterlands, which is a blockchain-based collectible card game that allows players to earn rewards in the form of cryptocurrency for playing the game. Splinterlands uses Polkadot's Substrate framework to provide players with a secure and reliable gaming experience. Overall, there are many different types of dApps being built on top of the Polkadot network that can be used for various purposes such as DeFi, asset management, and gaming.