WiFi Location ToggleWiFi Location Toggle helps to preserve your battery by turning off the WiFi radio when you aren't using it.
Most of us leave the WiFi radio on all the time. Android does a good job of making the process of switching between WiFi and our cellular carrier's data signal pretty seamless. When we leave a known WiFi access point, Android switches over to our carrier's 3G (or 4G) data signal, and everything continues working. When we're within range of a known WiFi access point again, Android automatically picks up the signal and we're connected via WiFi. It's very convenient, and we don't have to think about it.
The only problem with this approach is the way Android magically picks up our WiFi connection again. As soon as the WiFi signal is lost, Android begins periodically searching for known WiFi access points - that way as soon as it finds one, you're connected again as quickly as possible. But this periodic polling can drain the battery. Each poll is pretty minor - but over the course of, for example, a day at the office, it can add up to a surprising amount.
If you look at your battery history, you can see just how much WiFi is taking even when it's not actively connected. Android even suggests here that you turn WiFi off when you're not using it.
WiFi Location Toggle takes care of this automatically for you. It turns off the WiFi radio when you're not near a known WiFi signal. When you get near a location that is known to have a WiFi signal you can use, the radio is turned back on so that Android can reconnect.
First, you still need to set up your WiFi connection(s) just like you do now. WiFi Location Toggle doesn't keep track of your WiFi connection information, that's Android's job.
When you are connected to a WiFi access point, open the WiFi Location Toggle application on your Android device. You will be prompted to add this location:
If you agree, then the (approximate) location you are in right at that moment will be stored. Now, when you go far enough away from this location that your device loses its WiFi connection, WiFi Location Toggle will automatically turn off the WiFi radio to help prolong battery life. When you come back near this location again, WiFi Location Toggle will automatically turn the WiFi radio back on.
Later you can add additional locations the same way - when you are in a new place and are connected to a different WiFi access point, if you open WiFi Location Toggle it will prompt you again to add the new location. At that point, when you are near either saved location, WiFi Location Toggle will turn the WiFi radio on; otherwise, it will turn it off to preserve the battery.
You can add up to five such locations.
What WiFi Location Toggle does is allow you to mark certain locations as being near a known WiFi access point. When you go out of range of a WiFi connection, WiFi Location Toggle turns off the WiFi radio and begins checking your location - when you get near a location that you've designated as containing a WiFi signal, WiFi Location Toggle will turn the WiFi radio back on for you.
WiFi Location Toggle does not use the GPS radio. Instead, it uses your cell phone signal with functionality built into Android to get a general idea of your location. This can use some battery power, but not as much as the frequent WiFi polling that occurs when the WiFi radio is on and the device is not within range of an authorized WiFi signal.
Because this mechanism is less accurate than GPS, this does mean that WiFi Location Toggle cannot precisely pinpoint when you are within WiFi range. It will err on the side of turning on the WiFi radio when it detects that you are close to the designated area.
To save battery even further, WiFi Location Toggle will only check the location periodically - so you may be back at home for a few minutes before the WiFi radio turns back on.
In order to use this more battery-friendly mechanism, it is necessary that your Android device have this functionality turned on. If it is not already on, please go to your device settings and select "Location & security:"
From this screen, please make sure that "Use wireless networks" is checked.
Google has their own terms for offering this feature in Android, and their data collection has nothing to do with WiFi Location Toggle - WiFi Location Toggle does not share your location data with anyone. But if you are not comfortable with Google collecting this data and therefore are unwilling to enable this feature, I understand - but unfortunately WiFi Location Toggle cannot function without this feature, so here we'll have to part ways.
When you are not adding locations to WiFi Location Toggle, you can open the application to see a list of the places you have stored. The list will show the name you have given to each location, as well as an approximate distance from each one. If you are currently within range of one of the saved locations, it will be marked with a 
.
From the menu on this screen, you can change various settings for how WiFi Location Toggle will behave.
Among others, you can enable notifications - this will alert you any time WiFi Location Toggle decides to turn on or off the WiFi radio. By default these notifications are disabled.
Your saved locations can be viewed on a map in two ways:
WiFi Location Toggle also offers a widget that you can add to any of your home screens.
At the top is the WiFi radio status - green means the WiFi radio is on, gray means it is off.
On the bottom is the WiFi Location Toggle status - "AUTO" means that WiFi Location Toggle is enabled, and will turn on and off the WiFi radio as needed. "MAN" means that WiFi Location Toggle is disabled - just like before it was installed, it is up to you to turn on or off the WiFi radio manually.
Tapping on the widget will toggle the mode. If it starts in AUTO mode, tapping the widget once will switch off WiFi Location Toggle and make sure the WiFi radio is turned on; a second tap will turn off the WiFi radio; a third tap will re-enable WiFi Location Toggle, which will check the location and set the WiFi radio accordingly.
This can be useful if you want to temporarily turn on or off the WiFi radio and don't want WiFi Location Toggle interfering. Of course, you can also launch the main application, select Settings from the menu, and turn off WiFi Location Toggle that way as well.
Note: If you run into problems with the widget not responding after you first install WiFi Location Toggle, please try rebooting your phone. If the problem continues, or reoccurs again later, please let me know.
You can download this application for free from either the Android Market or from the Amazon App Store
If you have any questions about WiFi Location Toggle or encounter any problems using it, please contact me
Thanks to Mark Murphy and his Android books for helping me to learn Android development.
Also thanks to Don Madden for his suggestion to offer the option of disabling location checks when connected to a Bluetooth device.
Please also see my other application for Android, fix50.