Bill shock; it's the term the FCC uses for that "oh no!" feeling consumers get when they open their smartphone bill and find themselves slapped with overage charges. A survey [PDF] conducted by the agency shows that one in six cellphone owners have experienced bill shock at some point, and for 23 percent of those affected, the extra charges were in excess of $100. If you're a heavy Dropbox user or hooked on streaming Netflix, there is a way around those restrictive bandwidth caps: Wi-Fi. Any data downloaded through a Wi-Fi hotspot doesn't count against your monthly gigabyte allowance. (See our blog post on free texting apps to see how to save money by texting over Wi-Fi.) And with Wi-Fi hotspots popping up all over the place (including over 11,500 McDonald's locations), a small legion of helpful developers have whipped together apps that make staying off those 3G (or 4G) networks easier than ever.
Finding a Wi-Fi connection
Wi-Fi Finder (Android, iPad, iPod touch and iPhone: free)
JiWire's Wi-Fi Finder app does one thing, and it does it well: it points Android and iOS users towards nearby Wi-Fi hotspots. JiWire maintains a massive database of 650,000 hotspots located across 144 countries and users can submit new ones to the developers for inclusion. There are several filtering options - including filters for specific Internet providers and location types, such as hotels or restaurants - and free and paid hotspots are differentiated by color. You can even have it send you notifications or connect automatically when specific Wi-Fi signals (strength, location, etc.) are available. It's also possible to download JiWire's hotspot directory for offline usage, which could be a big help if you're in a dead zone or near your data cap. (It's also handy for international travel, as we discuss in another app roundup). KnowYourMobile.com has a brief review of the app.
Free WiFi Café Spots (BlackBerry, $4; Android, iPhone, iPad, iPod touch, $2)
AppMosaic's Free WiFi Café Spots app is available for a wide range of devices -- including BlackBerry -- but it has some drawbacks compared to Wi-Fi Finder. First and foremost, it costs money. Second, user reviews at Blackberry's App World, Apple's App Store and the Android Market are much more reserved. While the developer says that there are over 75,000 hotspots identified in 115 countries, users say that many areas simply don't have many hotspots identified. Otherwise, its functionality is largely similar to Wi-Fi Finder's. Despite its drawbacks, the app is one of the few Wi-Fi locators available for Blackberry devices, though the Blackberry version costs twice as much as the Apple and Android apps.
Training your phone
Locale is a flexible and easy-to-use automation app for Android that uses GPS in conjunction with programmable commands (called "Situations") to change the way your smartphone behaves in a given location. Using Situations, you can have your Android device automatically switch to Wi-Fi when, say, you enter your home or office, so there's no chance of accidentally racking up big mobile data downloads in familiar surroundings. This app offers a ton of other customization options as well; you can set your ringer to automatically vibrate at work or go silent during the night, for example. Plug-ins for advanced command options cost $1 each.
Tasker is a similar automation app that Tested.com says is even more powerful, though less user friendly than Locale. It's also a bit of a battery hog. Apple and Blackberry devices use a closed ecosystem and are more restrictive than Android about what apps can alter on a phone, so you won't find Locale alternatives on those platforms.
Tracking your data usage
The first step in avoiding overage charges is knowing how much data you actually use each month. Each of the three major platforms have apps that keep tabs on your data usage and will send you notifications if you're dangerously close to your cap. Richard Gruett's 3G Watchdog (Free) for Android, XVision's DataMan Free (Free) for iOS and dub3tech's Data Monitor ($3) for Blackberry can all help keep you informed and automatically reset with your monthly billing cycle after the initial setup. Some carriers also offer their own data usage tracking apps - see our related blog post on how smartphone data plans work, for more information.