Betterment is a great option if you want an automated low-fee portfolio from the biggest independent provider of digital accounts. Betterment was a pioneer in providing "set-it-and-forget-it" portfolios for a low-fee.
Consider Ally Invest if you want an automated IRA from a leading digital bank offering a range of other financial products (incl. bank accounts & mortgages).
Betterment
Automated
Ally
Automated