The need to open a door to your home with a metal key could be a thing of the past. Having a smartphone in your pocket, or smart watch on your wrist, might do the trick. It is just one application among many in the burgeoning Internet of Things, or IoT, which is turning technology on its head. 

Companies like Apple (NASDAQ:AAPL) and Google (NASDAQ:GOOG) (NASDAQ:GOOGL) are at the forefront of innovation in the IoT.

How will this affect investors?

Source: Google Images

Smart pants
A relatively new product is now capable of opening your door automatically. The Kevo app, loaded on your iPhone, communicates wirelessly with electronics embedded in the door jam. After you touch the lock, the door will then open. The system, which also includes a specially designed deadbolt made by Kwikset, was developed by Unikey Technologies.

Presently Kevo only works with iPhone 4s, 5, 5c, and 5s. Unikey promises an app that will work on smartphones running Google's Android. Advantage: Apple for now.

Smart watch
Kevo and similar apps will probably also work with Apple's long-awaited, and much rumored, smart watch to be released in the fall. Investors have been clamoring for a new product line to come out of Cupertino and they will likely get their wish before Christmas. One analyst thinks that the new device can add $4 per share to the bottom line, about 8% over the current consensus estimate for the next fiscal year. The device could act as some insurance if iPhone growth doesn't pan out.

Smart home
Apple recognizes the potential of the Kevo, and other applications of the Internet of Things around the house, and is offering developers a new tool specifically for this purpose. HomeKit was introduced at the company's Worldwide Developers Conference in early June and will become available in the fall, probably about the same time as the company's upgraded mobile operating system, iOS8. This could be a big deal in the long-term for Apple as the IoT is expected to become a 7 trillion dollar business by 2020. The company is likely to get a healthy piece of that pie.

Google is also active in the intelligent home, having recently acquired Nest, a maker of smart thermostats and smoke detectors. Although the company had a design issue that resulted in a product recall earlier this year, Nest should help Google investors in the long term as the focus moves to your home. 

Foolish conclusion
The Kevo keyless entry system is only one example of the potential of the rapidly growing Internet of Things. Apple investors will benefit as the company gets more involved in the business. HomeKIt is one such example of Apple building up its presence, which could result in more success and profit for shareholders.