How to tell malware apps from the real thing

A great way to evaluate the trustworthiness of an app is consider what permissions it looks for. A calculator app can be good, but if it wants access to your address book, then you should be wary. — dpa

It's no secret that not everything in app stores is really useful. Some apps are filled with advertising, others are badly coded and yet others are actually the work of scammers and cyber-criminals.

So how do you tell the good apps from the bad?

"A good indicator are the app reviews that users post in the Google Play Store or the Apple App Store," says Matthias Becker from Chip magazine. The reviews deal with an app's strengths and weaknesses from a user's perspective.

Markus Burgdorf from the consulting firm App Agency also considers these ratings to be valuable. "It helps to look at the screenshots, read the description text of the app carefully and then read the reviews," he says. Of course, one should be aware that some reviews can be fake.

Another way to evaluate the trustworthiness of an app is consider what permissions it looks for. "A calculator app can be good, but if it wants access to my address book I won't install it," Becker says.

Security, privacy and stability are the hallmarks of a good app, says Sven Rill, professor of mobile computing at the University of Applied Sciences in Hof, Germany.

"In the best case scenario, the app does without intrusive advertising, doesn't overdo in-app purchase offers and limits the permissions it demands to a minimum," he says.

"A good app makes my everyday life easier and doesn't make it any more complicated," Burgdorf says.

"There are often a large number of apps that to 80% are offering the same functionality," Rill says. "Whether one of these is successful depends on the remaining 20%."

The application should match its stated purpose, the professor says: "For example, a shopping list app does not need a navigation function."

Often you just have to try out an app to see if it's any good. But you should be aware of pitfalls – "Some apps are offered 'free' but in return they collect user data which is then used by the provider," Rill warns.

There are also apps that promise to unlock certain features in return for a good rating or which make money from users via hidden subscriptions, says app expert Burgdorf. Especially in games, there's a risk of spending too much on in-app purchases.

And there's also the danger of fake apps. "Successful apps are often faked," Burgdorf says. In those cases the name of a genuine app is slightly changed and screenshots and descriptions copied from the original listing. Such apps are often free but stuffed with ads or else don't work at all.

Some apps are really malware trying to collect smartphone data or make money by sending expensive text messages. Becker advises caution if an app sounds too good to be true. "If an app promises to make mobile Internet turbo-fast, you should first carefully read the app description and the user reviews." — dpa