Obamacare may get mixed reviews from the general public, but it's a cash cow for start-ups. And investors expect the money pile to get bigger.

More money poured into health-care start-ups than ever before this last January, with $390 million invested across 25 deals, according to Rock Health, a digital health start-up accelerator. That helped make the first quarter of this year the best quarter ever for digital health, with $700 million pouring into the sector, Rock Health reported last week.