Well, Super Mario Run [Free] seems to be the game that everyone on the planet is (still) talking about, with battle lines clearly drawn between the haters and the folks who are loving the game. If you're the latter, chances are you're doing everything you can to find all the hidden coins in the game. Well, TouchArcade forum superstar Andy C83 has put together videos of where all the secret black coins are in the game. If you're stuck on a particular level, or otherwise are just curious what top-tier Super Mario Run play looks like, look no further than these videos:
Super Mario Run Black Coins in World 1

Super Mario Run 1-1 Secret Black Coin Locations
Super Mario Run 1-2 Secret Black Coin Locations
Super Mario Run 1-3 Secret Black Coin Locations
Super Mario Run 1-4 Secret Black Coin Locations
Super Mario Run Black Coins in World 2

Super Mario Run 2-1 Secret Black Coin Locations
Super Mario Run 2-2 Secret Black Coin Locations
Super Mario Run 2-3 Secret Black Coin Locations
Super Mario Run 2-4 Secret Black Coin Locations

Super Mario Run Black Coins in World 3

Super Mario Run 3-1 Secret Black Coin Locations
Super Mario Run 3-2 Secret Black Coin Locations
Super Mario Run 3-3 Secret Black Coin Locations
Super Mario Run 3-4 Secret Black Coin Locations

Super Mario Run Black Coins in World 4

Super Mario Run 4-1 Secret Black Coin Locations
Super Mario Run 4-2 Secret Black Coin Locations
Super Mario Run 4-3 Secret Black Coin Locations
Super Mario Run 4-4 Secret Black Coin Loca...