The Twist app for iOS helps you share your estimated time of arrival with friends and colleagues, so they have an up-to-date sense of when they should expect you. The app uses your location and current traffic data to communicate an accurate arrival time. But it doesn’t start broadcasting your ETA until you leave.

The company, founded by serial entrepreneur and investor Bill Lee and Mike Belshe, an original Google Chrome team member,  just raised $6 million in funding from Bridgescale Partners and a number of other investors.

Users start a Twist by identifying where they are headed, which can be either a place or an address. The app plots a route for them by car, public transit or foot and provides an ETA. Users then decide with whom they want to share their Twist. The recipient gets a notice via text message or email when you leave your present location, as well as an estimate on your arrival time. Recipients can also request an update on your location while you’re en route. And if you run into traffic or stop off at a place, Twist updates your recipients on your new ETA. The app gives a notification when the user is one minute from their destination.

The service is kind of a mash-up between location sharing services like Glympse, which broadcast your current location, and Google Maps, which helps you navigate and plan trips. There are some nice touches like prompts to tell you when to leave to be on time, calendar integration which helps with easy routing to upcoming events and information about your destination. But the service has some limitations too. It only really works if you prepare ahead of time. You can program in favorite places, but you still have to remember to set a Twist beforehand to share your ETA. And it doesn’t work underground, which is how my wife and I usually travel.

I feel like Twist might be one of those apps you really wish your friends and family will use, but it might not be something you get into the habit of using yourself. Punctuality and communication are things that are easier to demand of others but harder to carry out yourself. But if you can remember to use it, Twist might be a nice way to be on time more often or, at least, it can help you be more thoughtful about communicating when you aren’t.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Forecast: Tablet App Sales To Hit $8B by 2015
• GigaOM Research highs and lows from CES 2013
• How HR can make the case for workforce analytics

The surge has come in large part from the growth of smartphones and the increasing awareness and acceptance of location-based safety services like Life360, which help parents stay abreast of their kids’ whereabouts. Chris Hulls, the founder and CEO of Life360, tells me the app has ridden the cell phone upgrade cycle as smartphones penetrate deeper into families. He said that 15 percent of the families on Life360 report that all of their members are on smartphones, a figure he expects to grow with each new upgrade. The average family size has also doubled in the past three months as families link up more smartphones to the service.

Life360 allows family members to keep track of one another through passive location tracking and active check-ins. Members can also send out panic alerts in the event of an emergency. Life360 is now processing more than 100 million location updates every day, more than any other family locator service.

The rise of Life360 is another sign of growth for mobile utilities, which serve the more basic needs of smartphone consumers. As we have pointed out before, the opportunities in mobile are shifting toward more simple, daily uses like health care, safety, education and fitness. While those types of applications haven’t gotten as much notice as games, entertainment and news software, they’re poised to take up more of consumer spending as mobile users expand their notion of what their smartphone can do.

Safety is definitely high on the list of more and more smartphone users. Life360 polled 500 of its users and found that 56 percent of parents gave their children smartphones for safety purposes, and 44 percent of users check in with family members one to five times a day. And 57 percent said they expect that in 18 months, every member of their family over the age of 13 will have a smartphone.

Life360 has relied on a freemium model, with most of its services available for free. That compares to its biggest rival Location Labs, which works through the carriers to provide a paid location-tracking service. Hulls believes that with the introduction of more free services like Apple’s Find My Friends service, location will increasingly be commoditized and apps will need to be free to attract users. But he said Life360 is looking to create more revenue opportunities by pursuing deals with third-party product makers and integrating with home control systems and car-tracking services. And it’s also looking at working with a 24/7 emergency assistance service.

Life360, which is part of the Facebook Fund and Dave McClure’s 500 Startups, has raised $2 million to date from Founders Fund, LaunchCapital, Mark Goines, Seraph Group, Kapor Capital and Venture51.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Podcast: Mobile winners and losers in 2012 and what to expect in 2013
• Analyzing the wearable computing market
• LTE-Advanced: what it is and isn’t