Got the idea from a reddit comment as ideas for dApps for beginners, decided to try it to learn how to make dApps.
Deployed on the rinkeby test network here
- Smart contract has a string field which serves as the comment from the last contributor
- To change the string, you must donate more than the last string-changer
- At the end of every month (using an oracle) or more easily: after reaching a certain threshold, the tokens will be donated to a chosen charity (see charities-accepting-ether)