For as long as Android has been around, people have been weary about or have complained about some of the permissions requested by apps when you install and intend to use them. While there have always been ways around this by way of rooting and flashing a custom ROM, in 4.3 Jelly Bean we saw a new feature called App ops that was implemented to help the user deny certain permissions to apps if they weren't comfortable with them, or just simply didn't want to grant the permissions. Most users probably had no idea this feature even existed inside Android 4.3, but we assure you it was there and it was a very useful tool. The best part is that you don't even need root access to use it.
Now that Android 4.4 Kit Kat is out, to some the question arose whether or not App ops would return. The answer is yes, App ops hasn't gone anywhere and you can still access it to feel a little more secure, and feel more comfortable with some of the apps that you use. While most apps generally don't ask for permissions to harm you or your information, there's still no surefire way of telling whether or not an app will have access to personal data that you don't want to give up. That's where App ops comes in and allows you to install an app while also denying the permissions to it that you don't want to grant.
This is particularly useful if you're worried about having your personal data stolen, but going so far as to just read permissions at all can do a world of good as well. App ops when it was introduced, had a default hidden view, so you couldn't just find it in settings or sitting in your app drawer. Much like developer mode in the about device section of settings, you had to know where to access it. This is still the case in Kit Kat, it's just hidden extremely well. You can use App Ops from the lars team to acquire access to this feature, and have better and more complete control over what apps have permission to do. If you want grab App ops for yourself, you can hit the link below to install it from the Play Store.