Warning: Never send anything directly to the HEX contract address! Always use a contract frontend. HEX sent directly to the contract address cannot be retrieved by anyone.
Smart contract frontends
Warning: You can verify the authenticity of any frontend by checking the contract address in the wallet transaction dialog box before you confirm. If you seek support or advice, only do so in publicly reviewed chat groups – only scammers will contact you privately to offer support (this is a general rule of all decentralized products).
Staker.app: An excellent Android and iOS app for following your stakes, HEX statistics, and HEX related on-chain transactions, it also acts as a HEX contract frontend for Gnosis smart addresses generated by the app; allows swapping and paying network fees with HEX, USDC or ETH; has referral program incentives.
In the unlikely case that all contract frontends go off-line, here are the instructions on using etherscan.io to interface the HEX contract.
APPs for mobile devices
Staker.app: An amazing HEX contract frontend and stake management tool.
Third party DAPPs
(Make sure you inform yourself thoroughly on how these APPs and DAPPs work.)
HEXref: Referral system contract for HEX.
Cryptocurrency market data aggregators