I have an idea to promote sport and give a chance for everyone to do a bit of charity. A runner/swimmer etc. would register to the app and be able to send his daily run distance/ swim distance from a mobile phone or GPS watch. Based on the distance a small amount of STEEM would be transferred from a special e.g. @charity account to randomly and/or collectively voted 5 charity projects a week. The charity projects would change every week and would receive a number of STEEM collected from last week's results.
Anyone could send STEEM to @charity account in the same way as with @null account is used to promote posts.