Crane monitors your posture in real time using on-device AI — then nudges you to move at the right moment, without breaking your flow. No cloud, no accounts, no data leaves your machine.
Software developers spend 6 to 10 hours a day seated in front of screens. The combination of deep focus, dual monitors, and marathon debugging sessions creates a perfect storm for musculoskeletal issues. The research paints a clear picture:
Forward head posture — where your head drifts ahead of your shoulders — is the signature developer ailment. According to a biomechanical model by spine surgeon Dr. Kenneth Hansraj (2014), at 60° forward tilt the head can exert up to 60 lbs of effective force on the cervical spine. Combined with prolonged static posture from reaching toward a keyboard, this creates compressive forces that contribute to tension headaches and chronic upper-back stiffness.
The cruel irony: most break reminders interrupt you at the worst possible moment. A generic 30-minute timer has no awareness of whether you are mid-thought or between tasks. Research by Mark, Gudith & Klocke (2008) found that it takes an average of 25 minutes to fully regain deep focus after an interruption — meaning a poorly timed break can cost you nearly half an hour of productive work.
Crane was designed by developers, for developers. Every feature respects the reality of deep-focus work while protecting your body from the damage of prolonged static posture.
The Deep Focus profile uses 60-minute seated blocks — long enough for a meaningful coding session, short enough to prevent the cumulative spinal compression that triggers pain. When the block ends, Crane guides you through a 30-minute recovery sequence: standing, walking, stretching, and exercise. You transition without losing context: adjust your standing desk, review PRs, or read documentation while your body recovers.
Crane uses TensorFlow.js with the MoveNet pose-estimation model to track your head position, shoulder alignment, and forward lean through your webcam. When you start hunching toward your monitor — the classic dual-monitor drift — Crane sends a gentle, non-blocking notification. All processing runs locally on your CPU. No images are stored, transmitted, or recorded.
Every 20 minutes, look at something 20 feet away for 20 seconds. Crane's ergonomic cycle timers naturally create opportunities for eye rest during activity transitions. Research suggests supplementary breaks may help reduce digital eye strain, though evidence for the specific 20-20-20 interval is mixed (Rosenfield et al., 2023).
Crane never steals window focus. Notifications appear as small, translucent overlays that fade after a few seconds. There are no modal dialogs, no forced pauses, and no gamification gimmicks. You see the nudge, you decide when to act. Your code stays in the foreground.
The Deep Focus profile is designed specifically for developers and other knowledge workers who need long, uninterrupted focus blocks. The 90-minute cycle breaks down as follows:
This cycle is backed by research on ultradian rhythms — the natural 90-minute attention cycles your brain follows throughout the day. A 60-minute focused block fits neatly within one cycle, and the 30-minute recovery sequence gives your spine decompression time, restores blood flow, and resets your posture for the next block.
If you use a standing desk, Crane handles the transition seamlessly. If you do not, the recovery intervals are a natural time to move, stretch, and refill your coffee before the next block.
For shorter sessions or faster-paced work, the Dev Sprint profile offers a 69-minute cycle with a 52-minute work block optimized for sprint-style development. It pairs well with Deep Focus — use Dev Sprint for code reviews and bug fixes, Deep Focus for deep feature work.
Crane runs entirely on your machine. There is no cloud backend for posture data, no telemetry, no analytics, and no account creation. Your webcam feed is processed frame-by-frame in memory and immediately discarded. The AI model runs on your CPU via TensorFlow.js — no GPU required. The only network activity is license validation for Pro users and app updates through the store.
This is not just a privacy feature. It is an architectural decision. Developers understand the difference between "we promise not to look" and "there is no server to send data to." Crane chose the latter.