Wren - Offset your carbon footprint by saving rainforests
Plantyflix - Watch Netflix and plant trees
YAYZY - Track the carbon footprint of each purchase in real-time
Treeapp - Plant a tree for free, every day, in less than a minute
Capture - A great free screen capture utility that allows you to capture either a window or the desktop and save it to either a file or the clipboard.
TreeMapper - TreeMapper is an easy-to-use tool for standardized on-site data collection on forest restoration.