# uranashel — On-device mobile instruments — iOS & Android

> uranashel is a three-person mobile software studio building on-device sensor and DSP instruments for iOS and Android: Wheria (indoor parking navigation), Estua (non-repeating sleep audio), Phyzix (pocket physics lab), Sonarish (acoustic diagnostics) and Stashio (semantic save-and-find). No ads, no tracking SDKs, no cloud requirement for core features.

Your phone is a lab. We ship the instruments. Navigation when GPS dies, sound that never repeats, a pocket physics lab, acoustic diagnostics — all computed on silicon, with no cloud dependency, no advertising SDKs and no analytics loop.

uranashel is a team of 3: **ntan** (Mobile & physics); **atuan** (Backend); **ktuyen** (QA).

## Apps

### Stashio — Save everything. Find by meaning.

*Semantic search · share sheet · Spaces*

Save links, photos, voice notes and PDFs via share sheet. AI cleans, tags and organizes into Spaces. Search everything by meaning.

- **Category:** productivity
- **Platforms:** iOS, Android, Chrome
- **Status:** live
- **Shipping since:** 2025
- **Last update:** 2026-06
- **Downloads:** 3K+
- **Stack:** Swift, Kotlin, Share Extension, Semantic search, SQLite
- **App Store:** https://apps.apple.com/app/stashio/id6753916323
- **Google Play:** https://play.google.com/store/apps/details?id=com.uranashel.stashly
- **Chrome Web Store:** https://chromewebstore.google.com/detail/stashio-%E2%80%94-save-to-remembe/ddifabdjihhojncjaeamfnjadnalmlga
- **JSON:** https://uranashel.com/api/v1/apps/stashio

### Wheria — GPS dies. We don't.

*IMU · baro · mag · dead reckoning*

Save your parking spot and walk straight back — even in deep underground garages where GPS dies. Motion, compass and barometer fusion. Widgets, Live Activity, parking reminders.

- **Category:** navigation
- **Platforms:** iOS, Android, Watch
- **Status:** live
- **Shipping since:** 2024
- **Last update:** 2026-06
- **Downloads:** 15K+
- **Stack:** Swift, Kotlin, CoreMotion, CoreLocation, WidgetKit
- **App Store:** https://apps.apple.com/app/wheria/id6785155247
- **JSON:** https://uranashel.com/api/v1/apps/wheria

### Estua — Sleep noise that never loops

*48 kHz · real-time synth · zero loops*

Never-repeating ambient for sleep, focus and recovery. Real-time on-device synthesis — no streaming, no account.

- **Category:** health
- **Platforms:** iOS, Android, Watch
- **Status:** live
- **Shipping since:** 2024
- **Last update:** 2026-05
- **Downloads:** 8K+
- **Stack:** Swift, Kotlin, AVAudioEngine, DSP, watchOS
- **App Store:** https://apps.apple.com/app/estua/id6784632438
- **JSON:** https://uranashel.com/api/v1/apps/estua

### Phyzix — Pocket physics lab

*100+ sensors · Euler/RK sims · EN/VI*

Your phone as a pocket physics lab. 100+ live sensor instruments, interactive simulations, calculators and guided experiments. EN + VI.

- **Category:** education
- **Platforms:** iOS, Android
- **Status:** live
- **Shipping since:** 2024
- **Last update:** 2026-04
- **Downloads:** 6K+
- **Stack:** Swift, Kotlin, CoreMotion, SceneKit, 100+ sensors
- **App Store:** https://apps.apple.com/app/phyzix-physics-lab/id6784482674
- **JSON:** https://uranashel.com/api/v1/apps/phyzix

### Sonarish — Listen like an engineer

*A-weighted · FFT · baseline diff*

Privacy-first acoustic toolkit: A-weighted noise meter, machine fault diagnosis vs baseline, PDF/CSV reports — all on-device.

- **Category:** utilities
- **Platforms:** iOS, Android
- **Status:** live
- **Shipping since:** 2024
- **Last update:** 2026-05
- **Downloads:** 5K+
- **Stack:** Swift, Kotlin, Accelerate, FFT, PDF export
- **App Store:** https://apps.apple.com/app/sonarish/id6785146314
- **JSON:** https://uranashel.com/api/v1/apps/sonarish

## The science behind them

- **Classical mechanics & IMU** — `F = ma`: Dead reckoning, step detection, attitude from accelerometer + gyroscope — how Wheria traces your walk indoors.
- **Barometry & altitude** — `P = ρgh`: Pressure → height: parking-garage floor estimation when GPS is useless.
- **Magnetometry & compass** — `B⃗ = B_E + B_dist`: Earth field + distortion handling for heading when you walk back to your car.
- **Acoustics & waves** — `v = fλ`: A-weighting, LAeq, FFT, baseline comparison — Sonarish and Estua built on wave physics.
- **Digital signal processing** — `X[k] = Σ x[n]e^{-j2πkn/N}`: Real-time synthesis, filters, envelopes — generative ambient in Estua without looping tracks.
- **Linear algebra & estimation** — `x̂ = K·z`: Sensor fusion, Kalman-style filtering, least squares — combining noisy measurements into one answer.
- **Electromagnetism & sensors** — `∇×E = −∂B/∂t`: Mag field, light, proximity — Phyzix exposes 100+ phone instruments as physics lab tools.
- **On-device computation** — `latency → 0`: No cloud required for core physics — privacy, latency and offline use by design.
- **Coordinate transforms & quaternions** — `q = w + xi + yj + zk`: Rotate sensor vectors between device, world and navigation frames — avoid gimbal lock in attitude tracking.
- **Sampling theory & Nyquist** — `f_s > 2·f_max`: Choose sample rates and FFT sizes so spectra and audio pipelines alias responsibly, not accidentally.
- **Psychoacoustics & perception** — `L = 10·log₁₀(I/I₀)`: Log hearing, masking, and calm UI timing — why Estua modulates slowly and Sonarish shows LAeq.
- **Vibration & harmonic analysis** — `f_n = n·f₀`: Bearings, fans and panels add predictable spectral lines — baseline comparison in Sonarish.
- **Numerical simulation** — `xₙ₊₁ = xₙ + h·f(xₙ)`: Euler and RK integrators for projectile, pendulum and wave demos inside Phyzix.
- **Optics & photometry** — `E ∝ I / r²`: Lux, exposure, color channels — phone light sensors as teachable instruments.
- **Statistics & inference** — `σ = √(Σ(x−μ)²/N)`: Confidence in noisy measurements — when to show error bars instead of fake precision.
- **Information capture & search** — `score(q,d) = sim(q,d)`: Full-text and semantic indexing for links, notes and files — Stashio organizes what you save.
- **Real-time embedded constraints** — `t_proc ≤ t_frame`: Fixed deadlines on audio and sensor threads — no malloc, no locks, no excuses.

## Operating principles

- **Silicon, not servers**: Core physics runs where the sensors live — in your pocket.
- **Zero surveillance economy**: No ad SDKs. No analytics loop. We sell tools, not attention.
- **Both platforms, same bar**: iOS and Android ship feature-parity — friends use both, we refuse to pick sides.
- **Monochrome on purpose**: Black, white, data first. Color is for signal, not decoration.

## Numbers

- Live sensor instruments: 100+
- Audio synthesis thread: 48 kHz
- Tracking SDKs: 0
- Shipped apps: 5
- GitHub stars: —

## Recent writing

- [Allan variance, or how long a gyroscope can be trusted](https://uranashel.com/blog/allan-variance-gyro.html) (2026-08-25, 21 min): We left five phones logging their gyroscopes overnight and used Allan deviation to work out how many minutes of heading Wheria can borrow between compass corrections.
- [An inaudible sonar that watches you breathe](https://uranashel.com/blog/sonar-breathing-doppler.html) (2026-08-18, 20 min): Sonarish's experimental breathing monitor drives the speaker at 19 kHz, listens on the mic, and reads 118 µm of chest motion out of the phase of the echo.
- [Semantic search with no server in the loop](https://uranashel.com/blog/on-device-embeddings.html) (2026-08-11, 19 min): Sentence embeddings, int8 vectors and a brute-force cosine scan let Stashio search your saved links by meaning entirely on the phone.
- [The lab behind the Lab page](https://uranashel.com/blog/lab-behind-the-lab.html) (2026-08-04, 18 min): A tech-stack tour of the browser demos on the lab page, from AnalyserNode fine print to hand-shifted spectrogram pixels, built with no framework and no trackers.
- [The battery budget of an always-on sensor app](https://uranashel.com/blog/battery-budget-sensors.html) (2026-07-27, 19 min): Four phones on a shelf, airplane mode, screen off, and five weeks of overnight battery logs to find out what each sensor really costs an always-on app.
- [Shipping the same day on two app stores](https://uranashel.com/blog/shipping-two-stores.html) (2026-07-18, 18 min): atuan explains the release train that moves five apps to two stores on the same day, with review-time numbers from the studio's own log.
- [Welcome to uranashel](https://uranashel.com/blog/welcome-uranashel.html) (2026-07-04, 20 min): Who we are, why five apps exist, and how this blog explains the physics behind them — in plain language.
- [Why everything runs on your phone](https://uranashel.com/blog/on-device-first.html) (2026-06-15, 19 min): Why parking, sleep audio, and noise meters must compute on your phone — latency, privacy, and offline garages explained step by step.
- [All 27 posts](https://uranashel.com/blog/)

## Contact

- Email: uralab95@gmail.com
- GitHub: https://github.com/uralabhub
- Country: Vietnam (VN)

## For agents and developers

- Public JSON API: https://uranashel.com/api/v1/ — read-only, no authentication, open CORS
- OpenAPI 3.1 description: https://uranashel.com/openapi.json
- API reference: https://uranashel.com/docs/
- Developer portal: https://uranashel.com/developers/
- Agent instructions (when to use uranashel): https://uranashel.com/agent-instructions.md
- llms.txt: https://uranashel.com/llms.txt

---

uranashel · [Home](https://uranashel.com/) · [Apps](https://uranashel.com/apps.html) · [Lab](https://uranashel.com/lab.html) · [About](https://uranashel.com/about.html) · [Blog](https://uranashel.com/blog/) · [Developers](https://uranashel.com/developers/) · [API docs](https://uranashel.com/docs/) · [Privacy](https://uranashel.com/privacy.html)

Machine-readable: [llms.txt](https://uranashel.com/llms.txt) · [sitemap.xml](https://uranashel.com/sitemap.xml) · [openapi.json](https://uranashel.com/openapi.json) · [API](https://uranashel.com/api/v1/)