Betterment's Everyday Savings account has no monthly fees, allows unlimited transfers, and offers FDIC insurance up to $1 million.
American Express' high-yield savings account requires $0 to open, levies no monthly fees, and earns a 2.10% APY on all balance tiers.
A money-market account is a hybrid savings and checking account, with high interest rates and, sometimes, access to a debit card and checks.
