Kiekmo was an Android app developed for Hamburg Sparkasse and designed to bring customers physically into the branch locations by offering a free item storage system (for use with online sales ala ebay). The customer would place an item within a locker provided at a Sparkasse branch and receive a lock code via the app. The customer would then provide the code to whoever purchased their item online and conveniently let the buyer access the item at will.
The app was written entirely in Kotlin and communicated with a GraphQL backend for updating comments, news feed and interaction with the physical lockers in branch locations. I personally worked upon the news feed, UI design and GraphQL integration.