Quite interesting, esp. the feature to accomplish something valuable collectively by working in a group. You may also think on the lines of BOID Team set-up to make a group more active as a whole vis-a-vis other group (teams). Points themselves should be transferable (donate-able) to charity instead of cash so that the charity could exchange them for the things they need from another sustainable company. Some sustainable ventures may also form a group to reward their group members with their products or services in exchange of points earned and gain more brand visibility & loyalty in return.

Will keep an eye on the development of this app.