Where can I find current eth staking rewards on dApps like rocket pool



I've been in the ecosystem for a while, but havent engaged in staking too much. I am looking to make an application that involves staking eth and I was wondering where I could find information about the following:

- The best developer oriented dApps for their users to stake eth - i.e. I want an API I can plug into

- The best rates for staking eth - i.e. where can I see Rocketpool's rate etc

- How often and with how much variance do I expect these rates to change?

Thanks a lot!