It is good you are looking into Bitcoin mining. While it sounds interesting to mine with Android phone it is generally not possible. Bitcoin mining requires huge computing power that specialized machines like ASICs have which are vastly more powerful and efficient than any phone. Trying to mine on your phone would just waste of time. Many mining apps for phones are actually scams that show you ads or trick you into cloud mining schemes which are also very risky. Instead of trying to mine it is usually much safer and more effective to buy Bitcoin directly from trusted exchanges.