BlockScout is a full-featured, open-source explorer that supports xDai. It lets you explore all transactional aspects on chain.
BlockScout access: https://blockscout.com/poa/xdai
BlockScout docs: https://docs.blockscout.com/
A second explorer is supported by AnyBlock Analytics and available at https://explorer.anyblock.tools/ethereum/poa/xdai/
We are fortunate to have the support of quite a number of wallets, including some amazing mobile wallets like AlphaWallet, DEX wallet and Poketto, and web wallets like Portis Wallet. You can use MetaMask, and Nifty Wallet and Saturn Wallet are additional web3 wallets similar to MetaMask but containing additional features that natively support xDai. The biggest wallet use case is Burner Wallet - as this is really designed for small, stable payments and for conferences and events. We invite you to check out our wallets page for more information.
Since xDai is an Ethereum-compatible sidechain, you can use the same tools (like Truffle), languages (Solidity) and environments you are used to using with Ethereum. With a few quick tweaks, your DApp can also be running on xDai. See Smart Contract Deployment for details.
This usually happens due to a MetaMask (MM) update and can be fixed by resaving the xDai custom network in MM. If you haven't setup xDai for MM yet, see these instructions.
1) Go to My Accounts -> Settings.
2) Scroll down and select Networks.
3) Scroll and select xDai.