In 2025, my family and I had a long streak of playing a Gomoku / Go Bang / five-in-a-row based game called OK Play. I built a web version so that we could play any time we wanted (i.e. on our phones after kiddos went to sleep).The first player to get five-in-a-row (horizontally, vertically, or diagonally) wins. In the first phase of play, players take turns placing their pieces next to existing pieces (always edge-to-edge; you can t place a piece with only a corner-to-corner connection). After players exhaust their pieces, play moves into the movement phase: you pick up an existing piece you own and place it according to the previous placement rules. During the movement phase, you cannot move a piece that would leave other pieces disconnected. Play continues in player order until someone wins.I wrote the app using Elixir s Phoenix framework with Daisy UI / Tailwind CSS for styling. The app is deployed on Gigalixir via its generous free plan. I am by no means a frontend developer / designer, so there s for sure better ways to implement things than what I have here. I mostly focused on making it mobile friendly and getting it to support light and dark mode. There likely exists browser / device specific bugs, since we ve only tested it out on our phones (iPhone 13 Pro, Safari / Chrome) and my computer (MacBook Pro, Safari). Happy to hear any suggestions, frontend or otherwise, if you have them!Developing this has been a real journey. Highlights have included learning about Gomoku and its variants, articulation points (and Trajan s algorithm for strongly connected components), and the Monte Carlo tree search algorithm (for the intermediate level AI mode I ve recently added for single-player use). Lowlights have all been CSS related.I d love to add a matchmaking mode in the future. I haven t really looked too much into the mechanics for how that s usually done though - it ll be a great learning opportunity!