Azumio, maker of the Instant Heart Rate smartphone app and other mobile biofeedback technologies, said Friday that it has acquired mobile health and fitness app developer SkyHealth.

With the purchase, a transfer of an unspecified amount of cash and equity, privately held Azumio, based in Palo Alto, Calif., now owns Glucose Buddy, which the company says is the world's most downloaded app for diabetes care, and Fitness Buddy, the top-selling paid health/fitness app on iTunes. Azumio also picks up SkyHealth CEO Tom Xu, who will serve as a partner and head of product development for the acquiring company.

"The future of bringing mobile health applications to a wider audience is here, and starts by creating a single source for the best mobile health and fitness solutions," Xu says in a press release. "Now, with Azumio, we have the resources and experience to create a mobile health and fitness platform that will impact hundreds of millions of consumers."

Azumio now claims more than 25 million downloads of its products, which also include the Instant Heart Rate, Stress Check, Stress Doctor and Sleep Time apps. "Both Azumio's and SkyHealth's mobile apps have seen massive adoption because we have been among the first to provide a simple solution to live a more healthy lifestyle, directly from your smartphone," Azumio CEO Bojan Bostjancic says in the same company statement.

"Smartphones are playing an increasingly important role in helping people improve their health and wellness, but success pivots around ease of access to new solutions -- mass adoption will only result from building apps that catalyze motivation and increase user commitment to their health and fitness goals," Bostjancic adds.

Azumio's own apps are available for Apple iOS and Android. The former SkyHealth primarily focused on Apple, but Glucose Buddy became available for Android a little more than a month ago. In May, the Glucose Buddy user base surpassed 10 million logs.