Sideloading means installing and running applications on mobile devices that haven’t been authorized or approved by the device’s official app store.
In the case of iOS mobile devices like the iPhone and iPad, users typically need to first jailbreak their device in order to sideload applications that aren’t authorized and available through the official Apple App Store.
For Android devices, while users can root their device to sideload applications without going through the official Google Play market, the mobile OS also offers a quicker and potentially safer method for sideloading. Instead of rooting the Android device, users can opt to simply check a box in Application settings to “Allow installation of non-Market applications.”
Security Concerns with Sideloading Applications
While Sideloading can give users access to applications that provide additional capabilities and features than they would otherwise have access to, there are security and stability concerns with sideloading mobile applications.
Sideloading can leave the mobile device more vulnerable to attacks by applications as well as use of the mobile device without the user’s knowledge. This results from applications in the official app stores of Apple and Android having to first pass the companies’ security policies before the apps can be authorized for installation by users.
Authorized applications as a result tend to offer better stability and security than non-authorized apps that need to be sideloaded.