The floating icon on Tango for Android is actually the Tango's solution to let you reply text messages faster than ever. When a new message arrives a pop-up icon appears on the screen and you just need to tap the circle, read the text message, and reply it without even bothering to open the Tango application itself.
But if you find this cool feature irritating, do as follows to hide/disable the floating icon on Tango for Android:
1. Open Tango on your Android phone
2. Go to settings by tapping the Gear icon from the sliding menu
3. Go to App Settings.
4. Make sure to unmark the Fast Chat option
**Note that this tip only works when you are using other applications as your default texting app.