Caliper: Vernier Trainer

MEASURE. PRACTICE. BUILD SKILL. Caliper: Vernier Trainer turns a mechanical vernier scale into short, visual exercises. Find the moving zero, read the main scale, match a vernier line, and put the measurement together. START FREE Level 1 contains five whole-millimetre readings. The guided tutorial is free too. No account is required. LEARN AT YOUR PACE Work through the current 30-level course, from whole and half millimetres to 0.02 mm steps. Practice reading, setting the caliper, and timed Speed rounds. Your progress and active round are saved on your device, so you can resume the same exercises. CHALLENGE YOURSELF Explore four Challenge worlds—Easy, Normal, Hard and Impossible—with 30 levels each. The free Easy 01 round shares Level 1. The remaining Challenge levels require Full Access. Earn achievements as you progress. ONE-TIME FULL ACCESS Unlock Levels 2–30, Read, Set and Speed practice, and the remaining Challenge levels with one non-consumable in-app purchase. The price is shown in your local App Store currency. Restore your purchase in Settings. Choose light or dark appearance and one of 11 in-app languages.