You need XPrivacy.
It is compatible with many versions of Android, including Android 5.1. From the README:
XPrivacy has been tested with Android version 4.0.3 - 5.1.1 (Ice Cream Sandwich, Jelly Bean, KitKat, Lollipop), and is reported to work with most Android variants, including stock ROMs.
It will allow you to control scores of different app permissions in android, with great detail and specificity.
It is gratis (free), but donations are accepted for the Pro version here.
Both the free and Pro versions are open-source.
There is an extensive thread for XPrivacy on XDA-Developers here.
XPrivacy requires the Xposed Framework on a rooted Android device.
Here are two screenshots of XPrivacy to give you an idea of the power. The first screenshot is of the basic interace. The second is of the expert mode, which shows the fine-grained control that is possible with XPrivacy.
Xprivacy (click images for larger variants)