How to send Emoji on your Android tablet or smartphone
First you need to check if your smartphone or tablet can display emoji. A simple test:
Go to the Wikipedia page for emoji, as shown in the screenshots below:
If the emoji are not displayed by your browser, you will need to root your device or use messaging applications already integrating emoji (Whatsapp or Google Hangouts).
Does your device supports emoji?
Go to Settings > About the device.
Android 4.1 or higher: If you are using Android 4.1 or higher, the emoji are integrated by default. You can activate the emoji keyboard by going to Settings > Language and input.
On the latest versions of Android the emoji keyboard is already activated (the name of the keyboard is not displayed in the "Language & input" menu)
Open the "Messaging app".
Write a new message.
Tap on the Smiley key to display the emoji keyboard.
For versions prior to 4.1: You can only use emoji through applications which natively integrates this feature.