The vast majority of apps in the official app stores (Google Play and Apple) are generally safe. The most common way mobile devices get infected is by "side-loading" apps from non-official app stores.
Side-loading involves transferring an app to your phone via USB, Bluetooth or WiFi. These apps are typically advertised as free versions of premium/paid apps.
Always download apps directly from the official app stores, confirm the publisher, and check the reviews.
OPSWAT MetaAccess is also able to scan installed apps on your device against with MetaDefender Cloud.
This article was last updated on 2018-02-21
(This article was changed to reflect the new name of OPSWAT MetaAccess on 2017-08-24)