Upgrade your dApp to xChain — Connext lets builders create secure xchain dApps (xapps). Our network is the only way to build xapps that retain the security of underlying blockchains. What are xApps? xApps (pronounced “zaps”) are decentralized applications that perform operations between independent chains/execution environments, Ethereum and Avalanche, Polygon and Polkadot, but also Optimism and Arbitrum, for example.