PrintBot
Brand: zenofx.com
Network printer driver for Android and Kindle Fire.
Supports ~6.000 printer models from all leading manufacturers (e.g. HP, Canon, Epson, Lexmark, Brother, Samsung). Works with most Airprint enabled printers.
Auto scan for printers
Free version allows printing of 3 images or PDF documents per month (after that, a watermark is added on each page). PDFs are restricted to 3 pages.
Pro version allows unlimited printing.