Sleep Terror Relief
The only app that detects a sleep terror or paralysis episode as it's happening — and wakes you before it escalates. Not a tracker. A responder.
A three-signal composite detection engine built from the ground up for the physiological reality of sleep terrors and paralysis.
HR (45%) + wrist stillness (35%) + body position (20%). A pattern, not a single threshold.
Elevated activity for terrors. Inverse stillness for paralysis. Two separate engines.
Composite trigger fires on-device — zero latency, zero cloud, zero transmission.
Gentle → Light → Firm → Strong → Full. No jarring alarm. A calibrated exit.
Apple Watch speaks your name. You surface safely, oriented, and calm.
Not a sleep tracker with extra features bolted on. A purpose-built detection and intervention platform — with tools no other sleep app has ever shipped.
After 7 confirmed clear nights, Zeno stops using population averages and switches to thresholds calibrated specifically to your body. Your resting HR, your stillness patterns — yours alone.
IntelligenceSleep terrors spike. Sleep paralysis flatlines. They are physiological opposites — and Zeno runs two entirely separate detection engines so neither condition can slip through the other's net.
EngineeringAll detection, all processing, all data — lives on your iPhone and Apple Watch. Nothing is transmitted. No servers. No cloud. Your sleep is not a product anyone else gets to see.
PrivacyWhen Zeno detects an episode, it sends a trigger signal to Apple Shortcuts — which fires your pre-configured camera automation. Zeno never accesses, holds, or sees any footage. You control what happens. The first time you've ever had timestamped documentation of what your body does while you sleep — automated, private, and entirely yours.
Pro Feature · AutomationVoice recording fires immediately after Zeno wakes you — while the dream is still raw and vivid. Tag episodes by theme. Chase. Falling. Confrontation. Build a record over weeks and months that reveals which conditions, locations, or stressors correlate with your worst nights. The beginning of understanding what triggers you.
Pro Feature · Voice + TagsProgressive escalation from barely perceptible to full intensity. Apple Watch Ultra's haptic precision makes each phase distinct. No alarm clock shock. No panic. A calibrated exit from the episode.
Core FeatureLong press any Clear night in History to flag a missed episode. Automatically excluded from the calibration baseline — the system learns from what it catches and what it doesn't.
IntelligenceSix commands wired — Start, Stop, Set Sensitivity, Log Dream Note, Last Night Summary, and more. All voice-activated. All fully integrated with Apple Shortcuts for custom automation.
Pro FeatureEvery episode Zeno captures — the timestamp, the physiological signature, the voice journal — becomes a data point. Over months and years, that dataset builds a map. Vision Pro's spatial canvas becomes the stage where your accumulated dream history is reconstructed in three dimensions: environments, recurring figures, emotional arcs across time.
This is not a feature you can build today. It requires the years of data Zeno starts collecting tonight.
Do your worst episodes happen when you sleep in a different city? At a specific altitude? After certain travel patterns? Zeno maps your real-world locations against episode frequency to surface the correlations your conscious mind could never detect.
Immediate start override for naps, irregular schedules, or the nights when you just know. No waiting for sleep onset confidence to build — Zeno arms itself the moment you tap.
Core FeatureRuns reliably for 9+ hours via HKWorkoutSession on Apple Watch Ultra. Your whole night, covered. No mid-session drops. No battery excuses. Engineered for the long watch.
Core FeaturePTSD-related sleep disturbances present identically to what Zeno already detects. The detection engine doesn't care about root cause. It responds to the body.
"Same intervention. Same result. A fraction of the cost. No waitlist."
The 7-day free trial lets you experience Zeno working. After that, staying protected is the only decision. No features negotiation.
After Apple's 30% cut: Core nets $4.89/mo · Pro nets $6.99/mo · Band Pro: $499 hardware + $34.99/mo net
From consumer sleep protection to clinical-grade nervous system intervention.
Zeno is the answer they've been searching for.
Built by someone who lived it. Designed for everyone who does.