Rensa Lab

Rensa Lab teaches chain puzzles — the kind where falling blocks clear in groups of four and set off chains — through a problem book. Place your pieces and see right away how many chains you made. ■ Explanations that tell you why When you miss, we show what actually happened on the board: which group you cleared too early, where the falling blocks joined only a few and stopped, and where the trigger was. Replay the answer chain one step at a time. ■ 7 units, 210 problems Basics → Find the trigger → Stair links → Sandwich links → Building 101 → Long chains → Advanced building. Start easy and work your way up. ■ Today's Problem A new problem every day at midnight — easiest on Monday, hardest on Sunday. Home Screen and Lock Screen widgets show today's problem and open it in one tap. ■ Easy on the eyes A paper-toned background, soft text color and large type. Every color has its own shape (triangle, diamond, square, hexagon), so you can read the board even if colors are hard to tell apart. Dark appearance is available in Settings. ■ Reminders only if you want them We offer a reminder only after you solve your first problem. Turn it on and you get one reminder a day, at the time you choose. ■ No account, no ads, no server Start right away without signing up. Your progress stays on this device, and explanations are made on your device without the internet. ■ How it works Unit 1 (30 problems) and Today's Problem are included with no purchase. Units 2–7 (180 problems) unlock with a one-time purchase — not a subscription — which also includes every problem added later. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://inphilchoi.github.io/chainlab-privacy/