ResistorVision instantly tells you the value of any standard beige 4-band resistor you point your iPhone’s camera at.

Unlike other resistor calculators, ResistorVision offers touch-free operation. Just place a beige 4-band resistor on a white background, with the tolerance band (usually gold or silver) on the right. Then point your iPhone’s camera at the resistor and the value is instantly shown at the top of the screen.

Note: Does not currently work with resistors with a blue body or resistors below 10 ohms.

Resistors can be purchased at any electronics supply store.