Designing a graphical interface for Arduino is easy
With ViSi-Genius from 4D Systems you can easily design a graphical interface for the Arduino. Pre-programmed buttons, meters, sliders, bar graphs and digits can be layed out on the screen and the ViSi-Genius automatically generates the required Arduino code. With the Arduino adapter you can connect the Arduino to the screen. The display with touchscreen is available with a diameter of 4.3" or 7".
ControlByWeb (Xytronicx, Inc) develops reliable I/O controllers which can be controlled via a web interface. The input of the controller can be used to monitor or to control a relay of a different controller remotely via internet. No software is required for setup or operation. Various controllers offer many advanced features. You can switch relays on and off at preset times. You can run scripts or send email alerts. You can also connect your 1-wire sensors. All ControlByWeb products can be controlled remotely with the CBW app and can be integrated in industrial systems using Modbus/TCP.
Small Arduino with Bluetooth LE can be controlled with iOS apps
The RFduino is a small, wireless, Arduino compatible microcontroller. It is a Bluetooth 4.0 Low Energy BLE RF module with ARM Cortex-M0 processor and RFD22301 chip. Via a Bluetooth connection with your iOS smartphone and the free apps the RFduino can be controlled. The RFduino is expandable with various small "shields". For example you can use the Colorwheel app for a RFduino with RGB Shield.
The Sparkfun RGB & Gesture Sensor is a small board with the APDS-9960 sensor. The sensor measures the ambient light, the colour, the distance and the movements. It is the same sensor as used in the Samsung Galaxy S5. The APDS-9960 has UV and IR filters, 4 diodes which are sensitive in different directions and an I2C interface. This sensor allows you to control your Arduino with simple hand gestures.