Can an app download itself? Judging by the number of downloads for some of the most popular apps, you would think that the answer is yes. But wouldn't this be dangerous? And how would these apps know where to go and what to do when they get there? In this post, we'll take a look at how app downloads work and what happens behind the scenes when you hit that Install button.
Before we go into the nitty-gritty:
Apps, can download themselves but usually only if they are part of a larger suite of apps or if they are being updated. Both scenarios require that the device/user permit them beforehand. They initially can't install themselves without confirmation by the device/user.
When you download an app from the App Store or Google Play, you usually need to actively press a button. You may even be asked for confirmation afterward. Depending on your settings you even need to enter your password or confirm the download with a fingerprint sensor. This is to prevent someone else from accidentally downloading an app that they don't want. And to stop an app from downloading itself.
This is common practice for all trustworthy app stores.
Which app stores can be considered trustworthy? As a rule of thumb, the well-known app stores are generally considered trustworthy. These include the App Store for iOS devices, Google Play for Android devices, and the Windows Store for Windows 10 devices.
There are other app stores that are not as well known, but that doesn't mean they're not trustworthy. In fact, there are many alternative app stores that are run by the manufacturers of the devices themselves. These can be a great place to find apps that are not available in the more mainstream app stores.
Here are a few other trustworthy app stores:
– Amazon Appstore für Android
– GetJar
– F-Droid
– SlideME
When you download an app from one of these stores, you can usually be confident that the app is safe and won't do anything to harm your device.
Of course, even the most reputable app store can't guarantee that every app is 100% safe. But they do have systems in place to vet the apps and remove any that pose a risk.
What about further installations once an app is on your device?
Now let's have a look at some more specific cases.
Can an app install other apps?
Maybe you are wondering if an app can trigger installations of other apps.
Normally, apps cannot trigger installations from other apps. This is becauseeach Android package file (.apk) installed on your device has its own Linux user ID. Linux is the operating system on which Android is based. This ID is unique and is used to create a sandbox for the particular app. This prevents it from affecting other apps.
If one of your apps would try to install another application, it couldn't create a new Linux user ID for the new app as this is something only your device itself can do (to be more precise: the system applet, having root access rights).
If you're wondering what else apps can do Can apps cause Ghost Touch? When the phone itself clicks...
Can an app download itself after installation?
This is a different case and may sound a little bit contradictory at first. Maybe you are even amused as there seems to be no reason for an app to download itself as the app is already installed. BUT (you know there would be a "but", right?) there is a process where this is happening. Quite frequently.
You know this as "Updating".
Every time a new version of an app becomes available you either have to trigger the update by confirming in the app or the app store. Once done, the app is actually downloading itself. The new complete app file is being downloaded and installed.
However, depending on the permissions you granted the app it might not need to ask for your permission each time but can update itself whenever needed - which is an installation.
Reasons an app might download itself are for closing security vulnerabilities, performance improvements or making features available that are not yet available in the app. For example, a social networking app might download new features that are being tested before they are released to the public. Or an app might need download new content, such as new levels for a game. Some apps also allow you to download additional features, such as new skins or characters. This can be done through in-app purchases, or it could be a way to get you to download another app that the developer has made.
There is huge advantage to having an app download itself: It it can be done automatically and in the background, so you don't have to think about it. Nothing worse than forgetting to update an app and being exposed to hacking as a consequence.
However, there are also some disadvantages. One is that it can use up your data allowance if you're not on a Wi-Fi connection. Further it can pose a security risk if the app provider itself got compromised or has malicious intentions in the first place, as malicious code could be injected in new versions of the app - which your app will then automatically download and install on your device. However, such cases are rare.
Can apps download when your phone is off?
As this question reached me several times I decided to include it here. And you don't have to worry:
Apps cannot download themselves when your phone is turned off. This is as in this state your software is not being executed, which is necessary for apps to perform actions.
However, if you have an app that is set to update itself automatically, it may begin to do so as soon as your phone comes back on. This is why it's important to be aware of the permissions that you're giving to apps when you install them. Some apps will require access to your data or storage in order to function properly, and if you're not comfortable with that, it's best to avoid those apps.
In general, it's a good idea to be cautious about any app that wants to download itself without your knowledge. If you're not sure why an app is doing this, it's best to do some research or contact the developer to ask why they're doing it. In most cases, there shouldn't be any reason for an app to download itself without your permission, so if an app is doing this, it's probably best to avoid it completely.
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