The robo advisor market just ventured a little deeper into the retirement arena with the launch of RetireGuide, which clues investors in on whether their investments send them in the right direction for a comfortable retirement.

RetireGuide, an advice engine, is the brainchild of automated investing service Betterment, which already offers customers a globally diversified portfolio of index-tracking ETFs, personalized allocation advice, and goal-based investing. Customers can open and customize regular investment accounts, traditional or Roth IRAs, trust accounts, and accounts for retirement income.

Where RetireGuide comes in is in helping clients to identify income in retirement and decide when it's possible to retire. The new application goes beyond typical retirement calculators, according to Betterment, in that it builds a customized savings and investing plan that takes into account all of the investor's investment accounts, including those with other providers, and even a spouse's holdings. It's then able to use all the data from those sources to put together a plan that's unique to the client.