Drag & Drop feature is available in Map Browsing mode.
If you hold your finger on start or destination flag, it will start jumping and then you can move it anywhere else on the map, which will change your itinerary and the route will be recomputed.
You can edit the route by holding your finger on the route a bit longer until blue flag appears, then drag the blue flag to a position, where you want to place a waypoint. The route will be altered to pass through that place.
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