Betterment for super easy "set and forget".

Betterment is a mix of auto managed index fund, and bonds. They also offer classic savings as an option. You can set the ratio of stock and bonds.

If you need the money again in less than a year, go 20% stock, 80% bonds.

If you need the money again in more than 2 years, go 80% stock, 20% bonds.

If you won't need the money for more than 3 years (and it's a predictable economy), go 100% stock.

Obviously watch the market. If there's talk of a looming mild burst, you can move to 100% bonds for a while.

If there's talk of a big burst and you feel uncertain about bonds, you can move into savings inside of Betterment, currently at 0.3% APY (it was much better with a healthy economy).

All of this is easily done inside the Betterment account with a couple clicks. You can move the money anytime you want.