Fundrise lets you invest in real estate with a $10 minimum investment. Use the link to sign up and make your investment. After your investment clears, you should receive $25 in bonus shares.
Use the link to sign up for Groundfloor. You'll need to invest at least $100 to get the credit. You should get a bonus $50 to invest 30 days after you make your initial investment (I get a bonus, too).