Here is another compact portable printer that combines with your smartphone to let you print your documents anywhere. The HPRT is an app-enabled thermal printer with 300DPI resolution. It weighs only 766g, so you can easily take it with you anywhere.
The HPRT printer comes with automatic paper suction functionality. Its battery life lasts up to 26 hours on stand-by. You will be able to print 70 sheets on a full charge. Expected to ship in September. More information is available here.