Some of the most interesting additions to Android often come from unofficial sources. Maligned though they may be, Google has incorporated many features previously only found in manufacturer skins into AOSP, and custom ROM developers add new features more or less as they feel like it, some of which are quite useful. For example, the CyanogenMod development team is working on a new integrated system for handling "locked" apps, applications that can't be accessed by the user without a password or other validation mechanism.
In the updated system users can assign protected status to any app on the phone, even system apps. One of the cooler ways to do this is to assign protected status to a folder on the homescreen (presumably only CyanogenMod's self-maintained launcher), then place apps inside of it. Once "protected," apps can't be launched anywhere in Android, including contextual links like a Chrome search or directly from the Play Store, without using the assigned unlock mechanism. This comes in the form of whatever the user has designated as a lock: a password, PIN, pattern lock, or even a fingerprint unlock for hardware that supports it. Check out the animation below, posted to Google+ by Cyanogen Inc. employee Adnan Begovic. The full animation is hosted on Streamable.
There's no word on when this feature will make its way into CyanogenMod, or the phones that have partnered with Cyanogen for official firmware. That said, the official CyanogenMod account shared the post on Google+, and that usually indicates that something is coming sooner rather than later.
- CyanogenMod Google+