Amazon was so impressed with this Alexa-powered video intercom, it invested in the company

Jonathan Frankel got the idea for his startup, Nucleus, when he was renovating a house in suburban Philadelphia.

"I have a wife and three very active little boys who like to demolish everything and we wanted to put in an intercom system," Frankel told Business Insider. "The quote came back at $5,000 for literally the same one my parents had put in 20 years before: the beige, analog, ugly system."

Frankel thought there must be a better way, so he went online to research Wi-Fi intercoms. He wasn't thrilled by what he saw, so he decided to build one of his own, a touchscreen device that can be placed anywhere inside a home, and responds to voice commands using Amazon's Alexa technology.

It's a lot more than a typical intercom: also lets you have audio and video chats between rooms, or with other homes that have the system. Plus, you can tap into Alexa to do things like read headlines or listen to music.

Nucleus went on the market last month and sold out on Amazon.com the first day.

Now, the company has restocked online and received new funding from Amazon's venture arm, the Alexa Fund. The Alexa Fund led Nucleus' $5.6 million Series A round, bringing the company's total funding to $10 million.

Frankel summed up having the support of Amazon in one word: Wonderful.

"They've really been fantastic partners and just good people who are willing to roll up their sleeves and do anything possible," Frankel said. "We had daily conference calls for months before launch."

The company has also had support from another major retailer, though a brick and mortar one: Lowe's.

Frankel said selling the devices - which cost $200 each when you buy more than one - in a physical retail location helped give the startup access to its target customers: regular families around the country.

Nucleus is has now sold in 47 states and Frankel said the device selling best in the South, in states like Texas and Florida.

"We'd rather have the housewife in Indianapolis buy this than the leading-edge technologist in San Francisco," Frankel said. "We are going after the mainstream family, people who have never heard the term 'IoT' or 'smart home' but they do have family members that they want to talk to."

Now, Nucleus will spend the next few months gearing up for the holiday season. The company also recently made an acquisition of a company called Ily, which has a similar mission and will help Nucleus improve its mobile capabilities.

Frankel said his goal going forward is to keep the device simple and easy to use, and to stay true to the company's mission: bringing families closer together - virtually, at least.

Disclosure: Jeff Bezos is an investor in Business Insider through hispersonal investment company Bezos Expeditions.