Flow Free, which can also be called "Flow", is a singleplayer puzzle game available for iOS, Android & Windows Phone developed and published by Big Duck Games LLC. It was originally released on iOS on June 7 2012. The game was shortly ported to the Windows Mobile platform and an Android version was released on June 29.

Game mechanics

You can draw a flow by running your finger from one dot to the next, starting at either of the colored dots. The flow will be built following through the squares you touch, and a colored glow will track your progress under your finger and brighten when you hit the corresponding dot, completing the flow. If you run through a square that is already filled, either by your current flow or another color's flow, the flow that was there will be truncated at that point and overwritten by your current flow. Due to this, it's not technically possible to overlap flows, but you can "paint yourself into a corner" by leaving yourself with no way to progress a flow without breaking another one. You will also break a flow by touching anywhere on it. When you break a flow, it breaks up to the point you touched and will start from the dot that the flow originally began. This is useful for replotting flows differently, as you can start right from the problem area leaving what came before intact.

Connecting one dot to its pair counts as a move, but the move is counted from the moment you start drawing the flow. Once you've started a flow you can take your finger off and look around the board or start on another flow, only being charged one move for that color. However, if you touch your flow again after connecting it, another move will be counted against you. The minimum amount of moves is the number of colored pairs, meaning only connecting each pair of dots once. You can still solve the puzzle with more than the optimal moves, but your finish will be marked with a checkmark instead of a star. You can come back and redo the puzzle at any time to upgrade your completion to a star.


The puzzle area is presented as a square grid made up of rows and columns of smaller squares. Inside the grid, some squares will be filled with colored dots, which are the ends of the flows you must make. Around the grid is information on the current puzzle and buttons with various functions. At the top of the screen is a back button on the left taking you out to the puzzle select screen, where you can jump to another puzzle or swipe over to puzzles of a different grid size. Next to the top back button is the current level you are on and the size of the current grid. On the right is your completion status, either blank if you haven't completed the puzzle, a checkmark if you've completed it with more than optimal moves, or a star if you've completed the puzzle with the minimum amount of moves.

Below the top line of information is the number of flows you've made out of the total number of flows, the number of moves counted against you so far and your best amount of moves, and the percent of the grid you've filled in. At the bottom of the puzzle grid are backward and forward buttons that take you to the previous and next puzzles, and between them is a restart button that will clear the grid and your moves, but not your best moves so far. Depending on how you finish the puzzle—either creating all flows without filling all squares, filling all squares with over the minimum moves, or finishing with a star—you will get options to move onto the next puzzle or keep trying.


Big Duck Games LLC has also released three expansions in the series. The first expansion, "Flow Free: Bridges", was released on November 8, 2012 at a fixed price. In this expansion, pipes can be made to intersect through pre-made bridges. The second expansion, "Flow Free: Hexes", was released on October 12, 2016, and features both free and paid premium puzzles. The gameplay is similar to "Flow Free" except the layout resembles hexagons instead of squares. The third expansion, "Flow Free: Warps", was released on August 8, 2017. This expansion allows you to have pipes warp from the edge of the map to the other edge of the map.