Access to it all
Google Map Layers
Google Maps: https://mt1.google.com/vt/lyrs=m&x={x}&y={y}&z={z}
Google Terrain : https://mt1.google.com/vt/lyrs=t&x={x}&y={y}&z={z}
Google Terrain Hybrid : https://mt1.google.com/vt/lyrs=p&x={x}&y={y}&z={z}
Google Satellite Hybrid : https://mt1.google.com/vt/lyrs=y&x={x}&y={y}&z={z}
https://mt0.google.com/vt/lyrs=s&hl=en&x={x}&y={y}&z={z}&s=Ga
Roadmap : http://mt0.google.com/vt/lyrs=m&hl=en&x={x}&y={y}&z={z}
Terrain : http://mt0.google.com/vt/lyrs=p&hl=en&x={x}&y={y}&z={z}
Altered roadmap : http://mt0.google.com/vt/lyrs=r&hl=en&x={x}&y={y}&z={z}
Satellite only : http://mt0.google.com/vt/lyrs=s&hl=en&x={x}&y={y}&z={z}
Terrain only : http://mt0.google.com/vt/lyrs=t&hl=en&x={x}&y={y}&z={z}
Hybrid : http://mt0.google.com/vt/lyrs=y&hl=en&x={x}&y={y}&z={z}
Other Map Servers
ESRI Worldview : https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}
Stamen Terrain : http://tile.stamen.com/terrain/{z}/{x}/{y}.png
Stamen Watercolor : http://tile.stamen.com/watercolor/{z}/{x}/{y}.jpg
Strava All : https://heatmap-external-b.strava.com/tiles/all/bluered/{z}/{x}/{y}.png
ESRI National Geographic : http://services.arcgisonline.com/ArcGIS/rest/services/NatGeo_World_Map/MapServer/tile/{z}/{y}/{x}