This is the NEXTION HMI a Human Machine Interface device that provides a GUI control of instruments that feeds from your microcontroller. The Nextion is simplified interface to visualize the process between a human and machine, these device is useful on IOT projects or simply an display to your project instead using a traditional LCD or LED display.
NEXTION included hardware and series of TFT boards along with a software editor to design your desired interface at the screen. The board uses a one serial communication port to communicate to your Arduino, RPI or AVR, and it works only RX/TX communication and let you avoid hassle of wirings, The NEXTION editor has an ability to provide a drag and drop component such as buttons, Pictures, toggle buttons, slider, progress bar, etc. to ensures that you spend less time in programming your development workloads with the help of WYSIWYG editor.
Download the GUI Editor software > http://nextion.itead.cc/download.html
Designer Starter Guide > http://wiki.iteadstudio.com/Nextion_Editor_Quick_Start_Guide
Download Arduino Nextion Library > https://github.com/itead/ITEADLIB_Arduino_Nextion