Draw and simulate digital logic circuits on your phone, tablet or desktop. Build circuits with logic gates, latches, flip-flops, clocks, switches, RAM/ROM, 7-segment displays and ready-made parts like adders and an ALU. Press Run and watch the signals flow, or step one clock edge at a time. NEW: Subcircuits. Save any circuit and reuse it as a chip inside bigger circuits. - Example circuits to learn from, including counters - Undo/redo, multi-select, text notes - Automatic saving, import and share circuit files - Dark and light themes, 9 languages The free version can save up to 2 subcircuits per project. A one-time purchase unlocks unlimited subcircuits. Found a bug or want a new component? Report it from the About page.