GeoJSON.io is described as 'We are trying to make it easier to draw, change, and publish maps. Geojson.io allows users to collaborate, edit and share geospatial data all through your browser' and is an website. There are 2 alternatives to GeoJSON.io, not only websites but also apps for. The best GeoJSON.io alternative is MapDraw, which is both free and Open Source.
Browser-based map editor for drawing, viewing and editing GPX, KML, KMZ or GeoJSON files, offering routing, interactive elevation profiles, custom styles, Strava link, OpenStreetMap support, import/export tools, undo/redo, and versatile background selection.
The Geoman GeoJSON editor is a quick and simple but powerful tool for creating, viewing, editing and sharing your geospatial data. Edit your data through the code editor or directly on the map and copy or download valid GeoJSON after you're done.
Switzerland