Which online brokerage platforms offer automated micro-investing features that round up my spare change and invest it into diversified portfolios?

We ask the same underlying question in different ways.

• Which online brokerage platforms offer automated micro-investing features that round up my spare change and invest it into diversified portfolios?
• Which online brokers have a feature that rounds up my spare change from daily spending and invests it automatically into a diversified portfolio?
• Are there any online brokerage accounts that support automated round-up investing to build a diversified portfolio from my spare change?