EasyStaking is a staking application for STAKE on Ethereum. There is no minimum required to participate. Rewards increase over time and are based on the length of time STAKE is placed in the protocol, and the total supply of STAKE. Rewards are earned at 15% APR, but are shared between EasyStakers and Liquidity Providers who provide liquidity to Uniswap.
POSDAO is staking on xDai, where you can run a node as a validator or delegate on other validators. There is currently a minimum of 200 STAKE required to delegate, and 2K Stake to validate. Rewards are earned at 15% APR, and participants receive this amount unless delegation share reaches more than 70% of a validating node.