Given the huge number of applications that appear on a daily basis, even Google can not keep track of and check how much they are safe.
Therefore, the security of the device depends primarily on you, and therefore you should consider it well before deciding to install one of these applications:
Weather forecasting applications
These applications are very popular, but many of them contain viruses. Recently, an application was published that contained a virus that collected data from phones and sent it to hackers who were interested in the credit cards of users.
Applications that "optimize" the phone
These applications promise to clear the cache from the phone, delete unnecessary programs, and speed up the device. However, numerous smartphones already come with these features, so applications of this type are unnecessary. In doing so, they consume battery life, do not speed up the system, and as a bonus come with ads.
Applications that increase the amount of RAM
If this sounds too good for you to be true - do not sin. These are optimizers that can temporarily delete cache files, and your phone can do it yourself. The thing is, you can not increase the amount of RAM that the phone already owns, and the topmost point is that these applications can very easily steal user data.
Applications for defragmentation
These applications have become popular because their creators have succeeded in persuading people that they are doing the same thing as computer programs. But smart phones do not have hard drives that should be defragmented. Therefore, these applications can only analyze how certain applications take up space. In doing so, they consume resources on the phone and can steal your personal information.