You have two issues:
- getting the app on your phone
- using the app
In pure Android terms, if you can obtain the 'something.apk' file for the app in question, you could use USB or Bluetooth or maybe even wifi to move that APK to you phone and install it. This is a process called "side loading."
CAVEAT: Some mobile vendors have locked their phones against apps that do not arrive through their marketplace services.
So where might you get this APK file? You could download it, or someone else could download it and send it to you somehow.
CAVEAT: Some jurisdictions have sanctions and penalties for accessing or possessing or helping someone access or possess "forbidden" things.
Now that you have the app installed to your phone, you launch it, enter required settings, and ... {time passes} ... enjoy. During the passing time, the app must use the available network connections and services to reach from your phone to the servers. In return, the servers must use the network connections and services to return your content.
CAVEAT: Some jurisdictions scan their networks for connections to servers and types of content they consider "forbidden." When they encounter "improper use" they interrupt what is happening. These interruptions may be a simple denial of service or the authorities may visit you with dire consequences.
In Western civilization, we take the liberty to access what we want whenever we want for granted. There are parts of the world where that is simply not the case. Some of those places have severe penalties for the exchange of any ideas that those in power deem unacceptable.
Good luck,
~~~ 0;-Dan
____________________
"Freedom" and "Liberty" are two distict and separate entities that are often confused. In the absence of physical restraints, I am "free" to swing my arms and kick my legs any way that I please. However, I do not have "liberty" to do that in ways that make contact with other persons or another person's property. I am "free" to say whatever thoughts come to mind using whatever words I choose. I do not have "liberty" to falsely call out "Fire!" in a crowded place or spread false statements without ethical, moral or even legal consequences.