A small iOS development studio

We build software that
respects the data you put into it.

TwistedData Studios is a tiny, opinionated studio shipping native iPhone and iPad apps. Three apps and counting — two on the App Store and a new one on the way. Each does its work on the device it runs on, without required accounts, without selling your data, and with every third-party SDK we depend on named openly in the privacy policy.

Dashboard Today 47 min sunlight 1240 IU vitamin D 207% of goal Last 7 days Deficiency Risk LOW 18 / 100
Portfolio Total value $127,492 ▲ $2,981 (+2.4%) today AAPL 120 shares · long $24,310 +1.2% NVDA 40 shares · long $31,879 +3.8% TSLA 250C 2 contracts · Jul 17 $1,840 −0.9% Leaderboard rank #142 Day streak 23
Today 72 HPA BALANCE Cortisol likely moderate today Today's recommendation Easy 30-min walk, then 5 minutes of slow breathing. Skip the hard session. HRV (SDNN) 58 ms ▲ trending up Deep sleep 1h 42m solid night
How we build

Three rules we don't break.

Every product we ship is held to the same three commitments. They shape what we can and can't build, and they're why our software feels different from what's around it.

On-device by default

What you enter and what we calculate stays on your phone wherever it can. Servers are an absolute last resort, and we tell you when one is touched.

No required accounts

Our apps work without you signing up for anything. Where we offer Sign in with Apple, it's optional and used only for a single, named feature — never as a gate.

Honest UI

Estimates are clearly labeled as estimates. Simulations are clearly labeled as simulations. We'd rather say "we're not sure" than fake precision.

Apps

What we ship.

Three apps: two live on the App Store and one on the way. SolGlow and CalmTide are companions — connect both and they share data on-device to get smarter. Click through to read each one's story.

Live · Free · Pro $7.99
SolGlow
Health & Fitness · iPhone + Apple Watch

A vitamin D companion for iPhone. Estimates the vitamin D you produced from sunlight today using your Apple Watch's Time in Daylight, your skin type, your location, and what you ate — all on the device.

  • Reads Apple Health Time in Daylight; writes vitamin D back as dietary samples.
  • Burn-risk warnings tuned to your Fitzpatrick skin type and the day's UV.
  • Weekly Sun Plan, Annual Plan, 60-day history with location-aware attribution.
  • No account. No analytics. Just a single UV-forecast network call.
Coming soon · Free
Hedge Fund CEO
Finance · iPhone + iPad

A polished stock-trading simulator. Start with a virtual $100,000, trade real US-listed tickers at real, delayed market quotes, and grow a portfolio you can actually be proud of — without risking a cent of real money.

  • Long, short, cover, and sell with realistic order handling and day P&L.
  • Full options chains: calls, puts, every expiry, live bid/ask, full Greeks.
  • Dividends paid on the ex-date based on what you held at the close.
  • Global leaderboard. 22 achievements. No required account.
New · Coming soon
CalmTide
Health & Fitness · iPhone + Apple Watch

A cortisol and HPA-axis tracker. Turns the HRV, sleep, and workout data your Apple Watch already collects into a weekly stress-balance score and an 8-week baseline-cortisol trend you can actually move.

  • Weekly HPA Balance Score from HRV, sleep, training load & breathwork.
  • Daily cortisol read with one smart, personalised recommendation.
  • 8-week baseline trend — the stress signal most apps never show.
  • Connects with SolGlow for morning-sun & CAR data. On-device, no account.
3
apps built
0
data ever sold
100%
native SwiftUI
required accounts
What's next

The road ahead.

A short, honest snapshot of what we're working on. We update this page when releases ship — not before.

Three apps, shipping one at a time.

We ship one focused release at a time — each when it's ready, not when a sprint board says it should. This list is kept current as builds ship and reviews clear.

  • Live · v1.4 SolGlow — vitamin D companion. Shipped Apr 2026, now on v1.4 “Celebrate the Sun.” See the update history →
  • In review · Jun 2026 Hedge Fund CEO 1.0 — stock-trading simulator. In App Review after a full review-hardening pass.
  • In review · Jun 2026 CalmTide 1.0 — cortisol & HPA-axis tracker that connects with SolGlow. In App Review.
  • Next SolGlow — an annual “Year in the Sun” recap and a roomier iPad layout.
  • Later CalmTide — multi-device iCloud sync and deeper SolGlow ecosystem features.
Press & resources

For writers and reviewers.

Short PDFs for each product with the headline numbers, the science (or the spec), and the privacy claims spelled out. Also where to point a link.