user15997: I am trying to figure out how i could make an android app like this one, https://www.youtube.com/watch?v=cVj0jqOlGXo but instead of transmitting through bluetooth it would transmit it through a usb cable that plugs from my phone directly into my arduino.

user16064: I think you may want to look USB Serial port communication in android. Some googling will help
 here's a nice example of such work, described in detail: 
http://felhr85.net/2015/01/09/a-dirty-and-quick-example-of-serial-port-communication-in-android/
And in case the codes/that source gets lost, here is the
GitHub link of the developer: https://github.com/felHR85/SerialPortExample

15997: <p>I am trying to figure out how i could make an android app like this one, <a href="https://www.youtube.com/watch?v=cVj0jqOlGXo" rel="nofollow">https://www.youtube.com/watch?v=cVj0jqOlGXo</a> but instead of transmitting through bluetooth it would transmit it through a usb cable that plugs from my phone directly into my arduino.</p>
 16064: <p>I think you may want to look <em>USB Serial port communication in android</em>. Some googling will help
 here's a nice example of such work, described in detail: </p>

<p><a href="http://felhr85.net/2015/01/09/a-dirty-and-quick-example-of-serial-port-communication-in-android/" rel="nofollow">http://felhr85.net/2015/01/09/a-dirty-and-quick-example-of-serial-port-communication-in-android/</a></p>

<p>And in case the codes/that source gets lost, here is the
GitHub link of the developer: <a href="https://github.com/felHR85/SerialPortExample" rel="nofollow">https://github.com/felHR85/SerialPortExample</a></p>
