There's not a lot new in Android 6.0 Marshmallow, which is now slowly making its way onto Android smartphones and tablets. Google characterizes Marshmallow more as an under-the-hood effort to improve system performance and stability. But one of the key new features for users is the ability to manage the privacy settings of applications.
How do Marshmallow's privacy controls compare to iOS's?
For several versions, Android has shown users what data and services an app wants to use when the app is installed, but you could only accept or reject them all. Also, you could not deactivate permissions (such as to your contacts or camera) later.
By contrast, iOS has for several versions let you manage specifically what data and services each app can use after you install it. iOS 9 continues to work the same way.
Although Android's new controls for managing specific privacy permissions is welcome, it's inferior to what iOS provides. The reason: iOS easily shows you all the apps that use a specific type of data or service, then lets you manage the access to that resource in one place. (In the Settings app, tap Privacy and the specific function to which you want to manage access, then use the switches to control each app's access to that function.)
Android Marshmallow, by contrast, hides that information, although it is available if you know the secret sauce.
The Marshmallow UI steers you into checking each app's settings and managing the access settings separately. (In the Settings app, tap Apps, tap the app you want to manage, then tap the Permissions section. Use the switches to enable or disable access to specific features.) Thus, it's hard to get a clear picture of how exposed any type of data or service is across your smartphone or tablet.
If you want to see all the apps that use a specific type of data or resource, here's how: In the Settings app, tap App, then tap the Settings icon (the gear) to open the Configure Apps screen. Normally, you use the More menu (via the ... icon) in Android for accessing additional features, but in this case you use Settings. In the Configure Apps screen, tap App Permissions to get a screen that shows each permission. Tap a permission, as you would in iOS's equivalent but more accessible screen, to see and manage which apps use those permissions. It shouldn't be that hard to find.
Of course, a diligent user will eventually find that obtuse path or go into each app's settings in Android Marshmallow and check into every permission. (iOS lets you work that way too; if you tap an app in Settings, you can see its privacy permissions and adjust them.) But Android's approach is also more apt to let apps get more access to your private data and system services than you'd like or realize.