Support

FishRuler measures using the LiDAR scanner, so it needs an iPhone that has one. That means the Pro models: iPhone 12 Pro / Pro Max and later. On a device without LiDAR you'll see "This device does not support LiDAR" and measuring won't be available. Please check your model before purchasing.

Point the camera at the fish and tap once at the nose, once at the tail. A line is drawn between the two points and the distance is shown in centimetres. If a tap is off, drag the marker to fine-tune it, and press Reset to clear the measurement for the next fish.

The value on screen is a guide, based on what your device's depth sensor actually measures. Results are steadier in good light, with a steady hand, and with the fish laid as flat as you can manage. Treat it as a practical number for use out on the water.

Please don't use it for that. For tournament measuring rules, legal size limits, or official record claims, always confirm with the measuring device those rules require. Checking the regulations in effect where you fish is up to you as the angler.

Yes. FishRuler runs completely offline. Rocky shorelines, backcountry streams, docks, out on the boat — it measures the same with no service at all.

It's a one-time purchase. Buy it once and there's nothing further to pay. No subscription, no in-app purchases and no ads.

No. FishRuler collects no data at all and nothing is sent off your device. The camera feed is processed right on the phone solely for measuring, and the app never saves it.