Startup of the week: Sunu

What they make: A wristband that uses sonar to alert visually impaired people of nearby obstacles.

Why it’s cool: Have you ever wondered what it’s like to be a bat, and navigate through the dark using sound waves to detect obstacles? Strapping a Sunu band to your wrist might be the next best thing. The band emits a high-frequency sound wave that bounces off objects in the user’s path, and translates that information into gentle vibrations. By feeling the change in vibrations on his or her wrist, a blind user can navigate around people and other obstacles in a crowded room or sidewalk, find doorways, and more.

I tried one out recently during startup accelerator Y Combinator’s demo day, where Sunu made its debut at the Computer History Museum in Mountain View, Calif., along with 123 other companies. The device was lightweight and comfortable, and felt similar to a smart watch or wearable exercise monitor. When I strapped it on, in the midst of a crowd of people, I felt a continuous, light buzzing on my wrist. The buzzing stopped as I stepped out of the crowd, and started up again when someone came toward me.

Every five seconds a blind person goes to the hospital for a head injury, according to the Sunu founders. They’re trying to prevent those injuries from occurring. The founders say their wristbands fill a major gap in services for blind people, who basically have two options now — a $30 white cane, or a $30,000 seeing-eye dog.

Where they stand: The first Sunu bands are set to ship to customers Oct. 1, and the company already has raked in $25,000 in pre-order sales over the past four weeks.

To order: Sunu bands cost $249 during the pre-order period. Visit http://www.sunu.io/index.html? to learn more or purchase.

What will they think of next?

You already have countless apps and websites to help you find that special someone — from Match.com to Tinder. But what about high-tech solutions for when that relationship goes south?

That’s where Oakland-based Hello Divorce comes in. The startup is trying to make divorce less painful by providing an online platform that guides you through every step of the process. You can try the company’s “divorce navigator,” which offers templates, guidance for filling out the mountain of necessary paperwork, instructional videos and other legal advice.

It was founded by Erin Levine, a Bay Area attorney who specializes in family law.

“I want to help savvy, diverse, outside the box thinkers navigate the divorce process when they want and where they want,” she wrote in a news release.

Learn more at hellodivorce.com.

Run the numbers:

So far this year, 128 startups have achieved coveted “unicorn” status — meaning they’ve hit a valuation of $1 billion as a private company, according to a new study by venture capital database PitchBook. That’s up from just six companies 10 years ago, and it’s the highest number on record. But the rate at which companies are earning their horns has slowed. There were 43 unicorns minted in 2014, and 44 the following year. Last year saw just 18. With four months to go, this year already has seen 17 new unicorns.

Still, there’s been no rush from these companies to go public, PitchBook reports.

Quotable:

“Losing my suit hurt, but I didn’t have regrets,” diversity advocate Ellen Pao writes in an excerpt of her new memoir, “Reset,” which is set to hit shelves next month. The book chronicles her legal battle against her former employer, Silicon Valley venture capital firm Kleiner Perkins Caufield & Byers, which she lost in a high-profile trial last year. “I believed I had an obligation to speak out about what I’d seen.”

Pao also opens up about some of the personal consequences of the legal battle, including her miscarriage: “I felt, in that moment, that Kleiner had taken everything from me.”