Mobile Fundamentals · Mobile Operating Systems · Lesson 2 of 4

Permissions

Answer real permission prompts and see what you've handed over.

Allow or deny?

Some data on your phone is private enough that apps have to ask before touching it. These requests are called permissions. Location, camera, microphone, contacts and photos are the big ones. The first time an app needs one, the phone shows a prompt, and your answer decides what the app gets.

Location usually comes with several choices. On recent Android phones the prompt typically offers:

• While using the app, which lets it see where you are while you're using it
• Only this time, which gives access for now and makes it ask again next time
• Don't allow, which blocks it completely

iPhones offer similar choices with slightly different wording, such as Allow While Using App and Allow Once. Letting an app track you all the time, even in the background, is a separate and bigger step that both systems make you grant deliberately.

Location history can reveal your home, your workplace and your daily routine, so choose carefully. You can change any answer later in Settings.

A hiking app called TrailSnap is opening for the first time. Answer each of its prompts on the simulated phone.

Trust your gut

Every permission prompt is a small trade. You hand over some data, and in return the app does something useful for you. A good rule is to give an app only the permissions it obviously needs for its job. Security people call this idea least privilege, and they apply it everywhere.

Start by thinking about what the app is for. A maps app needs your location. A video calling app needs the camera and microphone. A flashlight app needs to switch on a light, and that's about it. When a request doesn't fit the app's purpose, the app may be collecting data to sell, or it may be malware.

Saying no is usually safe. A well-built app keeps working and only loses the feature that needed that permission. You can also review and change permissions later in Settings on both Android and iOS. Newer versions give finer control too, like sharing only selected photos instead of your whole library.

Be especially careful with contacts. Sharing them hands over your friends' and family's names and numbers as well as your own.