ColorCheck! vs AngleMetric

■ What color is it? Curious about the color in a photo? Check the average color using your camera or album. ▣ Copy RGB values and hex codes. ▶ Color Check! ◀

Put a drop of water on a surface and watch what it does. On a clean pane of glass it flattens out. On a waxed car hood it beads up into a little dome. That shape — how much the drop sits up or spreads out — is the contact angle, and it tells you a lot about the surface underneath. Contact angle is one of the oldest measurements in surface science, and for a long time you needed a benchtop instrument that costs as much as a car to get a number out of it. This app does the core of that job with the camera you already carry. Here's how it works. You put a droplet on your sample, line the phone up, and the app finds the edge of the drop and fits it to theoretical curves. You get the contact angle in degrees, left and right sides, plus a fitted profile drawn over the live image so you can see exactly what it measured. There's a side-on mode for the classic profile view and a top-down mode for flatter, more wetting drops where you enter the volume and it works back to the angle. Who actually reaches for this: A grad student checking whether the oxygen plasma run actually changed the surface energy, before committing a whole experiment with it. An engineer qualifying a coating or a cleaning step and needing a number to put in the report. Anyone comparing materials — is this polymer more hydrophobic than that one, did the treatment hold up after a week, is the surface as clean as it's supposed to be? And also curious people in the kitchen (where much of surface science was founded). Contact angle is a nice way to show a kid why rain sheets off a freshly waxed surface but soaks into an old one, how succulents collect water, how a butterfly keeps its wings clean. What you get: - Side-on and top-down measurement modes of droplets (as small as 5µL with newer phones) - Contact angle in degrees - A gravity-adjusted Young-Laplace numerical fit that can work with larger droplets - Local Machine Learning droplet identification and profiling - Live overlay so you can see the fit on the real drop - Records saved on your device, with CSV export for your own analysis Lighting, focus, and a steady hand all affect the reading, same as any optical method. Used carefully it's repeatable and quick, which is often exactly what you need when measuring in the field, on unwieldy or oddly shaped samples, or for a quick check. A low-cost 10-100µL micropipette is an excellent accompanying purchase. Free to try. A one-time Pro purchase or subscription enables saved records and exports. An Analytical Lab plan adds an auditable 21 CFR Part 11 enabled database, biometrics, data webhooks and a guided ASTM D8597 measurement flow for teams that need process discipline. Due to the nature of the program phones with an ultra-wide angle lens (i.e., iPhone 11+) image small droplets better. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ AngleMetric Terms of Service: https://entropymetrics.com/CAterms.html Privacy Policy: https://entropymetrics.com/CAprivacy.html