Geo Data Collector supports GeoJSON

GeoJSON is an open standard for simple geograhical features and non-spatial attributes/properties 

GeoJSON supports the following geometry types: PointLineStringPolygonMultiPointMultiLineString, and MultiPolygon. Geometric objects with additional properties are Feature objects. Sets of features are contained by FeatureCollection objects.

You can use QGIS Desktop, OGR2OGR command line tool and and other resources to convert data and create GeoJSON

ESRI ArcMap and ArcGIS Pro Geoprocessing tools also supports converting data to GeoJSON JSON To Features (Conversion)