When you're eagerly installing the latest must-have disappearing photo app or addictive puzzle game, how much time are you likely to spend reading through the required permissions before you accept them? Probably not enough.
It's tempting to give the permissions screen no more than a cursory glance when installing apps, not least because they're often couched in technical language that can be difficult to decipher. Here we'll show you how to check the permissions your apps are already using and explain the jargon behind some of the most common ones.
Checking app permissions
Head into Settings >> Apps on an Android device, tap any app and then scroll down to the bottom of the page to see the permissions it's been granted. You can't switch individual options on or off, so it's all or nothing. If you see an app that you're not happy with then tap on Uninstall to get it off your device.
This being Android, there are various third-party apps you can install to give you a better look at app permissions and more control over them.
One such tool is SnoopWall. It's not for the faint-of-heart, but it comprehensively audits and manages the security setup on your phone or tablet. SnoopWall installs itself as an administrator in order to manage your device settings, so you'll need to disable this through the app's menu should you eventually want to uninstall it.
You may also remember that Google has been experimenting with an App Ops feature that lets you disable particular permissions on individual apps (much as you can in iOS). This has yet to be officially released and may not appear anytime soon; the Android team argues it would be confusing for users and a headache for developers, though there are many who would like to see this level of flexibility introduced.
So until that happens, here's what you're stuck with, and what it all means.
Common permissions explained
Modify, delete and read storage: Gives an app permission to access the storage on your device in order to save and edit files. Most apps will require some kind of access, if only to keep temporary logs on your device. Any app with these permissions can also get at the public folders on your Android phone or tablet, like the photo gallery and default music folder.
Find and use accounts on the device: Google, Facebook, Twitter. These accounts are often integral to the way we use our phones, letting us tweet from anywhere or access Gmail from multiple apps. This permission gives an app the ability to tap into these accounts without jumping through hoops to make life more convenient for you. Bear in mind that the app can potentially access any information stored in the account in question.
Full network access: Just like the software on your laptop, most apps require some kind of Internet access, whether it's for software updates, syncing or retrieving data from online resources. Retrieving adverts to display is a common use here. As with most permissions, you're relying on the app in question to use this privilege responsibly.
Phone status and identity: Don't panic: this doesn't mean it can listen in on your phone calls. This permission enables apps to recognize when a call comes in and give you the opportunity to answer it, pausing the current app in the background in the meantime.
Prevent phone from sleeping: When your phone or tablet goes into sleep mode, it can interrupt certain processes, such as data being written to the internal storage. This permission enables an app to keep your device 'awake' while important system tasks are being carried out; it can also be used by video players, for example, to keep the screen on.
Read and send text messages: Plenty of apps want to replace your phone's SMS functionality, and this permission can also be used to automatically scan your incoming texts for authorization codes (used where two-step authentication is involved). This is another classic example of a permission that can either be very useful or very worrying depending on your perspective. Make sure that if an app is asking for this, it has a clear use for it.
Read your contacts: This isn't something that you want to give away without good reason, but a whole range of apps ask for it anyway. The ability to share content with your friends in some way is often the underlying purpose, though the permission might also be requested so that the app can quickly auto-complete the names of your contacts whenever required.
Sticky broadcasts: If you see a reference to a "sticky broadcast" in a permission list it concerns the way apps communicate with each other. Android typically treats each app as if it were a separate user: broadcasts enable these apps to talk to one another (sometimes without your knowledge), and the stickiness or otherwise controls how long they hang around in memory for. If an app wants to communicate something to other apps or to Android a long time after the event then it uses a sticky broadcast. The example often quoted—though it's broadcast by Android itself rather than an individual app—is a low battery level. Apps still need to know this information even after the alert has originally been sent.
There are plenty of other permissions to consider (and the number continues to grow as apps get more complex), but these are the ones you'll run into most frequently. A variety of different apps can help here too, such as BitDefender's Clueful Privacy Advisor, which explains more about the data each app has access too.
Are my apps safe?
Most of the time, app permissions are a question of trust; you're relying on the apps and their developers to behave properly. An app that has permission to save a photo to your phone can also delete pictures, an app that can read SMS codes can also harvest personal texts, and so on.
The majority of permissions are open to some kind of abuse, so ultimately we're often indebted to the rest of the user community, eagle-eyed security experts, or Google itself to spot malicious behavior before it causes serious problems. Be careful when installing little-known apps with no background or history, and keep an eye out for permissions that don't seem to fit.
If you're unsure, check the app's website and accompanying documentation for more details. The most diligent apps will explain each permission and why it's required for the peace of mind of their users. If you have your doubts, ask the developer for an explanation before installing.
Remember that the ability for apps to talk to each other and the default tools on your device are easy to take for granted. It may seem odd for a mapping app to ask for access to your phone dialer, but this lets you dial a restaurant right from the maps screen—otherwise you'd have to memorize the number, close down maps, and then open up the phone app.
What about iOS?
Apps work differently on iOS, as you've no doubt noticed if you're an iDevice owner. Apple has a more stringent admissions policy when it comes to allowing apps in the App Store in the first place, and anything you choose to install automatically has access to a group of basic permissions by default. Extra permissions—access to your photos, your location, and so on—are requested via pop-ups on the screen the first time they're needed, giving you the choice of enabling or disabling them piecemeal.
From the Settings app, tap Privacy and then choose a particular permission to see the apps that have been given the associated rights. Permissions can be revoked by tapping the relevant toggle. The app itself remains on your device and will still run, but its functionality may be restricted (there's little point in installing Snapchat if you don't let it access your camera, for example).
Hopefully this gives you a clearer idea of the permissions you are likely to come across and the actions behind them. We'd also recommend regularly uninstalling any apps that you no longer use, as this is the safest way of ensuring that they're not doing anything they shouldn't be.