This is the map style used in the the android application StreetComplete, an easy OpenStreetMap editor.
There are three variations on the style available: light, dark and satellite-style.
This map style's design goal is to serve as a background map, used solely for visual orientation and navigating as a pedestrian while using the StreetComplete app during an (on-foot) survey. It is designed to not visually distract the user from the quests that are displayed on the map. Elements that are neither relevant for orientation nor for quests asked in the app itself, are not displayed at all.
Every vector map tiles hoster has his own schema, so every map style is per se only compatible with the schema it was created for. The style was originally created for are for the mapzen/nextzen schema. However, it has been adapted to work (with some reservations) with other vector tile schemes as well. It is available for: