AutoArduino allows you to control your Arduino pins right from Tasker. Install the following sketch on your Arduino to use AutoArduino: You can set any output pin's digital or analog value from a Tasker action. This allows you to do just about anything on your Arduino from your Android device with the advantage of never having to change the code in your Arduino itself!
The app was originally designed by joaomgcd and it is listed among the Productivity category. Over 5K users downloaded and installed AutoApp for Arduino and the most recent update was on Jun 24, 2016. The tool has the overall rating 3.8 on Google Play.