Delta: Mind the Gap
Rate it before. Rate it after.
Only for iPhone
$9.99 · Designed for iPhone. Not verified for macOS.
iPhone
Ever notice how the stress you imagine beforehand is scarier than the thing itself? You start with dread, and afterwards it wasn't that bad.
Delta helps you see one thing clearly: the gap between what you expected and what actually happened. It's simple. Before you start, rate the stress you expect, 1 to 5. Afterwards, follow up and rate how it actually felt. The difference between the two scores is Δ (Delta): the shadow of trees your brain invented to talk you out of it.
Every entry is a card. As the cards add up, an automatic report does the math for you: most things aren't as bad as you imagined. When your guesses drift closer to reality and Δ approaches 0, you graduate.
That's why Delta is a one-time purchase with no subscription. The whole point is that one day you won't need it anymore.
Some quiet details:
· A home-screen widget, Sun, Moon & Forest: by day, a bigger gap casts a longer shadow; by night, a bigger gap fills the forest.
· Four themes: Oak, Sepia, Indigo, Blush.
· Export your report as an image, in three time ranges.
· Face ID app lock. Removing a card moves it to Drafts first, so you can always take it back. Full backup and export.
The developer is a medical PhD student who wanted to study her own anxiety the way she studies everything else, and walk out of its shadow.
An honest note: Delta is a tool for self-observation. It doesn't diagnose or treat anything, and it isn't a substitute for professional help. If anxiety is seriously affecting your life, please reach out to a professional first.
Privacy: Delta runs entirely on your device. No network requests, no data collection, no accounts. Every entry is yours alone.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
In this version:
· Background thumbnails in Settings now match your theme.
The developer, jiebin huang, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- jiebin huang
- Size
- 16.6 MB
- Category
- Lifestyle
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Simplified Chinese
- Age Rating
4+
- 4+
- Copyright
- © 2026 Xinyue Xiao
