If you’re an old-school, ex-film photographer like me, you probably still have a fondness for light meters. These days, with everything being automated, most people don’t carry one around in their camera bag. Luckily, there’s an app for that! The Lumu Light Meter app—from Lumulabs—is well-designed, easy to use and extraordinarily useful. Lumulabs has thought of options that I could have never dreamed up, which help to make it the best incident meter of its kind.

When you’re running around out in the field, find a scene you want to shoot. Once you open up the app, you can keep it simple—just point your camera at a scene and adjust your ISO and shutter speed. Want to get more complicated? Select the Exposure Compensation tool in the bottom lefthand corner, where you can raise (or lower) your EV up to +1. Or you can pop over to Filter and set your Neutral Density filter option.

There’s also a Spot Metering Settings menu. You can adjust everything from your Parameter Steps (which lets you adjust the aperture, exposure or ISO) to your Maximum ISO Value. My favorite little nugget is the option to switch your Camera Type from Digital (the default) to Analog. When you’re working with a digital camera vs. an analog camera, you’ll be dealing with minor calculation adjustments and they actually thought of that when they made this app. Makes me smile every time I whip my phone out.

Lumu Light Meter is not a camera app. I make this mistake sometimes when I’m staring at a scene through my viewfinder and want to take a photo; it just meters the situation for your larger DSLR, nothing more. For that, try popping open VSCO.

If you want or need more metering capabilities, Lumulabs sells Lumu Power, a $299 color and light meter that is designed to plug into the Lightning port on an iPhone or iPad. It includes two diffusers, a dome diffuser that measures ambient light and flash exposure, and a flat diffuser for measuring luminance, color temperature and chromaticity. You don’t need the Power to use Lumu Light Meter, which is free as an app for both iOS and Android devices.