Devunt Rise sharpens your Fermi estimation skills through power-of-ten challenges
60+ questions across 5 challenge packs • 47 reference anchors • Offline chain builder
Download Devunt RiseClaim your starter pack and accelerate your estimation mastery
Download required to redeem codes. All features work offline. No subscription or network needed. Educational use only.
Every feature designed to train your intuition about scale and magnitude
Graded in decades, not percentages. Get within one power-of-ten for a Bullseye. This mirrors real-world engineering thinking where ballpark accuracy beats false precision.
Break impossible questions into sequences of familiar quantities. Turn "saliva in a lifetime" into heartbeats × days × decades, then compare your chain to the expert model.
Train 90% confidence intervals until your gut instinct matches statistical reality. The app tracks your hit rate and shrinks overconfident ranges over time.
Reveal systematic patterns in your estimates. Are you always low on tech stats? High on cosmic scales? The bias map exposes hidden blind spots for targeted practice.
Seconds in a year: 31.6 million. Minutes in a year: 526 thousand. Carry these mental anchors and multiply any per-second rate into annual totals instantly.
The weakest 10 anchors resurface automatically. Drill them until recall is instant. Real estimation means pulling numbers from memory, not reaching for a calculator.
Structured practice that builds genuine estimation intuition
Devunt Rise was created for professionals who estimate before they calculate. Consultants sizing markets, scientists checking experimental orders, students learning Fermi decomposition. Version 2.1 brings refined calibration tracking and expanded anchor library based on user feedback from technical communities.
Engineered for precision, built for offline reliability
Devunt Rise stores all 60 challenge questions, 47 anchor quantities, and the entire scoring engine locally on your iOS device. No server calls. No account creation. No analytics tracking your estimation patterns. The app launches and functions identically whether you're online in a city or offline in a remote field station.
The chain builder interface lets you construct multi-step decompositions using a visual node system. Each node holds a quantity, unit, and power-of-ten exponent. Multiply nodes together and the app tracks accumulated error through the chain, showing exactly where your intuition diverged from the model solution.
Calibration rounds use interval mathematics under the hood. You provide lower and upper bounds for a 90% confidence range. The app measures interval width in decades and penalizes both overconfidence (too narrow) and excessive caution (too wide). Over repeated rounds, it nudges you toward statistically valid gut estimates.
iOS 2.1 • Fully offline • No account • Install in under 60 seconds
Download Devunt Rise NowFree download • Educational content • Works without network • Age rating: 4+ • Updated 10.11.2026