iKringLoop

iKringLoop was built as a tool to help lower trash buildup in the city of Amsterdam. People tend to throw out perfectly usable things in the trash when they do not want it anymore, so the idea was to connect those people to others who might actually need those items. This way, people could give away their unwanted items to others directly, and the city would be able to deal with a lesser amount of trash.
It started with people communicating with others nearby via the mobile app, which meant people only had access to things nearby. Eventually, collection centers were set up so that items could be moved to other locations to alleviate long trips.  
Architecture
This tool had a Native iOS and a Native Android application. They can still be found in Google’s Play Store and Apple’s App Store. In addition, a Web Service API was built in PHP to act as the backbone for data collection.