Gasbag, an iPhone app they developed to show drivers gas prices at nearby filling stations. (Speaking of Japan, a “large proportion” of the app’s users are in that country, Johnson says, so there’s also a Japanese version of the app.)
As the vigorous discussion around new services like Facebook Places shows, any mobile or Internet application that relates to location raises a host of social and technical questions, not the least of which are about privacy. I plied Johnson about a number of these issues.
Are there really a lot of families where everyone, including the kids, has an iPhone? “There is certainly an argument that kids don’t yet have smartphone, but the data we’re getting from people now is dispelling that notion,” Johnson says. “Kids are getting phones younger and younger, and more often than not they are getting the phones they want. There are some interesting effects where parents are giving their two-year-old iPhone 3GS to their kids when then get an iPhone 4.”
GPS is a battery hog—how do you keep a location-based app running all the time without draining the phone’s battery? “The biggest problem is getting 24-by-7 accuracy without killing the battery,” Johnson acknowledges. “We think we have come a long way on this. The real trick is to treat this as an optimization problem. If you are driving up Highway 101, you wife doesn’t actually need to know that you have moved every 5 seconds. She only really cares when you’re leaving, when you are about to arrive, and when you’re nearby. Sampling at exactly the right time, and only for as long as you need to get the right location fix to provide the right information, gives you the right tradeoff. We only turn the GPS on for 5 to 10 seconds at a time, at the right times. If you’re staying in the same place, the background tasks don’t wake up until you start moving.”
How do you get beyond the early adopters with an app like this—the families where the parents are tech geeks? “The families using our service aren’t unusually techie families,” Johnson answers. “Some are. But we have one user in Boston who is a police officer with a young daughter, and he just wants a little extra security. He’s not a techie guy, just a normal, concerned parent. There are a lot of those out there who have iPhones right now.”
How do kids feel about having their parents monitor their locations? “We’re specifically looking at 11- to 14-year olds,” says Johnson. “It’s not a case where you have a 17-year-old high school senior who is maybe staying out late. Those kinds of privacy tradeoffs are much harder to negotiate, and the use case is not so clear. But when you have a child who has spent most of their time with you or in school, and now they’re at the age where they are starting to become independent, that is when you have these classic tradeoffs—‘Okay, you can go to Bobby’s by yourself but I want you to call me when you get home.’ That’s pretty standard stuff, we just make it easier. From the kid’s point of view, it’s actually less work for them. They don’t have to call when they get home. They don’t have to call to find out how far Mom is from picking them up. It all just works.”
Wouldn’t it be easy for kids to turn off the app if they don’t want to be tracked—or does it have some kind of childproof password protection? “We have built it to allow kids to turn it off, and the reasoning behind that is that we want to make it a collaborative thing between the parent and the child,” says Johnson. “This draws on my background as a teacher. If you set things up where the kids and the parents are battling over control, the parent can’t really win. If you set it up as a collaborative network, where the kid feels they are engaged and involved, the psychological motivation is
