We're making an exception by covering a paid tweak that has absolutely no functional value but this tweak is seriously so cool that it deserves a mention. If you've envied iPhone 5s's TouchID security feature and have secretly hoped that it's available for your iPhone (5, 4s, 4) too, this will interest you.
Bio “almost” brings TouchID to older devices. With Bio, you put your finger on the screen, it scans your fingerprint and voila! The iPhone gets unlocked. It all looks cool and stunning, really. And if we were writing a satirical post, we'd stop right here.
In terms of design, Bio is perfect. But it has no functional value. The tweak is best if you want to fool your friends into thinking that your older iPhone has got some magical capability to scan your fingerprint and use it to unlock the iPhone. Ultimately, Bio is just an eye-candy tweak. But it does prevent unlocking the iPhone by anyone through what is called ‘secret steps.'
Found under the preferences of Bio (in Settings), secret steps is a list of options/actions that you can do to unlock the screen. Since the default “slide to unlock” behavior is removed (for the phony but really interesting TouchID-like scanning feature), your iPhone can be unlocked through a secret step that you have configured (and so, only you know of it).
Secret steps include things like flipping the volume switch, tapping the Control Center clock or calculator or camera, swiping twice/thrice in a given direction etc.
So typically, with Bio installed, you'll show off the magical fingerprint scanning capability while performing the secret step too. This will unlock the device and hopefully, your friends will be fooled into thinking that you've got TouchID-like authentication.
Among the other things that can be configured/customized, you can pick a shape for the scanner and have an image picked from camera roll to be the background for the scanner. You can also customize the scanning line color, the text color, opacity, size, animation speed etc.
My only complaint is the price tag. For a simulator, $1.99 is definitely high.
Bio is available on the BigBoss repo. It's a fancy tweak but a damn good one at that.