How To Install Apps On Iphone Without App Store
Sideloading Apps Maybe the simplest way to add apps to your iPhone without using the App Store is by using a technique called sideloading. Sideloading is the name used for installing apps directly on the iPhone rather than using the App Store. It's not a common way to do things, but it's possible.
Can you download apps other than App Store?
From your smartphone or tablet running Android 4.0 or higher, go to Settings, scroll down to Security, and select Unknown sources. Selecting this option will allow you to install apps outside of the Google Play store. Depending on your device, you can also choose to be warned before installing harmful apps.
How to install apps outside of Google Play - CNET