eCAD

Draw a circuit, then run it. eCAD is a schematic capture environment with a real simulator behind it — place parts from a library that carries the symbol, the footprint, the simulation model and the orderable part number in one file, wire them up, and press play to watch voltages, currents and waveforms on the sheet itself. Throw switches and turn pots while it runs. Every pin in the library carries an electrical type, so the rules check catches two outputs fighting or a supply with nothing driving it before the board is ordered rather than after. When the design is settled, export a bill of materials that already knows what to order, and print the sheet with a proper drawing border and title block. PCB layout is coming; the browser tree already shows where it goes.