StakeCube.net released the BTC interest function in beta version at the end of march — and operates now completely automated for 3 high market cap coins in total.
Interest rates on BTC, LTC and DOGE: 0.015% per day and 5.627% per year.
StakeCube will increase the rate for BTC, LTC, and DOGE to 0.02% daily starting from 01.07.2019.