WalletConnect is an open source protocol for connecting decentralised applications to mobile wallets with QR code scanning or deep linking
Wallet Connect can be used to connect a Cosmos wallet both on the Desktop browser and the Mobile native browser. WC have recently stopped v1 and have asked dapps to move to v2
Leap Mobile Apps have added support Wallet Connect v2 and here are the official docs for integration : https://docs.walletconnect.com/2.0
There are two ways you can integrate with Wallet Connect v2 on your dapp -
Wallet Connect has a library called web3Modal which helps generate the QR and handle the connection. It takes care of opening the application
Cosmos Kit is an open-source library that helps to connect to any cosmos wallet easily. You can check out their docs here for installation.
Additionally, you can also check their docs on connecting Leap using walletConnect v2 here