This app enables you to monitor Arduino via Wifi/3G/4G. Up to six channels can be monitored simultaneously. The measured quantities and units can be manually defined.
Setting up the whole system is very easy. You will need Arduino Uno / Mega with ethernet shield + specific Arduino code to use this app. You must know how to configure your routers port forwarding settings in case, you want to monitor your Arduino outside your Wifi network.
System uses analog channels A0 to A6 as default. You can use other channels as well, both analog and digital, instead of the default channels by modifying the Arduino code. Few examples are given in the following url where you can also download the Arduino code.
https://drive.google.com/folderview?id=0B4_uJI1BOUG5Zy1yVTYySVl6RGM&usp=sharing
Check the links to get instructions how to set up the system.