[4][5] StreetComplete marks places and things in a map overview for which data in OpenStreetMap is missing or possibly no longer up to date.

Users can complete this missing data by answering simple questions (called quests).

The quests are designed in such a way that answering them on site is quick and easy and no special expertise or prior knowledge is needed.

[5] A unique feature of the app compared to other OpenStreetMap editors is the use of gamification to make solving the quests fun and competitive.

Users collect points with every quest they solve and can thus improve their national and global rank.