Digispark kickstarter CJMCU Micro Attiny85 module Mini USB Development Board for Arduino usb

The Digispark is an Attiny85 based microcontroller development board similar to the line, only cheaper, smaller, and a bit less powerful. With a whole host of shields to extend its functionality and the ability to use the familiar Arduino IDE the Digispark is a great way to jump into electronics, or perfect for when an Arduino is too big or too much.

Feature 1 
8K flash (about 6K after bootload)
Support Arduino IDE 1.0+ (OSX / Win / Linux)
Can be powered by USB or 5v or 7-35v (automatic matching) additional power supply
USB Embedded (Serial Debug)
500ma 5V regulator on motherboard
USI of I2C and SPI)
3 Pulse width modulation on the needle (more likely to use software pulse width modulation)
ADC on 4-pin

Feature 2 

6 I / O Pins (2 are used for USB only if your program actively communicates over USB, otherwise you can use all 6 even if you are programming via USB)
8k Flash Memory (about 6k after bootloader)
I2C and SPI (vis USI)
ADC on 4 pins
Power LED and Test / Status LED (on Pin0)
PWM on 3 pins (more possible with Software PWM)