Normally, "restricted access" is something you despise. No one likes to be told they can't do something, especially when it comes to the Internet. Unfortunately, having web access at all times can not only eat away at your wallet, but make your day less productive overall, so some sort of moderation is needed.
That's where Internet (Data/Wifi) Lock Lite comes in, which was created by MSAPPZ after the developer found his prepaid balance depleted thanks to his mischievous kid watching too many Lady Gaga music videos on YouTube. The app basically prevents internet access by adding a secret PIN that needs to be entered in order to connect to the Web.
I'll be showing you how it works on my Samsung Galaxy S3, but it should work fine with most Android phones running 1.6 and higher.
The app is lightweight and dead easy to use. All you need to do is install the app from Google Play link or .apk provided in the XDA thread, set up your PIN, and you're done.
You can then choose Data, Wi-Fi, or Both to PIN protect each access point.
NOTE: You might need to restart your device in order for the Authorization Required screen to appear.
Now, when you let someone borrow your phone, or give it to a child, you will not have to worry about them incurring unwanted data charges or accessing the internet without your authorization.
It's like a child lock and penny-saver all rolled into one.
Now, while the app is most useful for preventing unwanted data charges, it can also be used to prevent people (including yourself) from accessing the internet, even over Wi-Fi.
While you will obviously know the PIN that you created, adding that extra barrier does actually decrease the likelihood of unnecessarily browsing the web. Same goes for adding a PIN or Passcode to your lock screen. Without a PIN or passcode, you're more likely to open and close your phone needlessly, compared to if there is a barrier in place.
Altering the ease of access is a very legit tool in deterring unwanted usage.
Internet (Data/Wifi) Lock Lite is ad-supported, so if you' like to remove the ads, you can opt for the pro version of Internet Lock (Data/Wifi Lock) for $0.99, but if you don't mind ads, the free app is good enough.