Circuit Forge

Circuit Forge is a proper logic-circuit designer, not a quiz app dressed up as one. You place logic gates — AND, OR, NOT, XOR, NAND, NOR — onto a workbench, drag wires between their pins to connect them, and toggle input switches on and off; the whole circuit evaluates live, so every output LED lights or dims the instant the logic actually resolves. Because the evaluation is a real boolean engine under the hood rather than pre-scripted outcomes, you can wire up genuinely non-trivial things — a half-adder, a multiplexer, a flip-flop — and they behave exactly the way the underlying logic dictates, propagation and all.

Beyond free-building, Circuit Forge includes a truth-table view that reads your current circuit and computes its complete input-to-output table automatically, so you can verify a design does what you intended across every possible input combination. A set of challenge levels gives you a target truth table and a limited set of gates, asking you to build a circuit that satisfies it — turning the sandbox into a real puzzle of logic minimization, not just free play. Your builds save to a local library so you can come back to a complex circuit later or reuse a sub-circuit you're proud of.

The app is built as a full multi-screen tool — a workbench canvas you can pan and zoom across, a component tray, a truth-table panel, a challenge browser, and a saved-circuits library — with all designs stored locally on the device. No account, no ads, no connection required; the entire logic engine and everything you build lives on your phone.