We used [PosWallet] to stake Stratis Token, however not sure if they are planning on continuing this Service in the future, would definitely recommend Staking with them for now just for the convenience. Right now, I can't seem to find anything that allows Staking Stratis besides the official Client, my Friend is planning on getting a Raspberry Pi to specifically stake this particular token, this will be the dedicated unit to run 24th & 7 Days a Week, it will waste little Electricity and should be able to provide 100% uptime
RE: How to Stake Stratis Tokens using the Official Wallet Client - Altcoin Guides #1