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My First App, Revived After 15 Years

Mind-Reading is the first iPhone app I ever made, back in 2011. Six years after it disappeared from the App Store, I brought it back with the help of AI. It's a little number trick that guesses the number in your head.

Free on the App Store

For iPhone (iOS 15.0 or later). Available in English, Japanese and Simplified Chinese. No internet connection or account needed.

View on the App Store

The Story

  1. 2011: The first app I ever made

    It's a silly little app. Yet somehow, it was downloaded 50,000 times in over 100 countries.

  2. 2020: Gone from the App Store

    I didn't update it for newer versions of iOS, so it was removed from the App Store.

  3. 2026: Revived with the help of AI

    Working with AI, I updated the 15-year-old source code to run on today's iPhones and put it back on the App Store after six years.

Anyone could make an app this silly. But for me, an ordinary office worker at the time, it's where everything I do today began.

How to Play

  1. Start screen with the title "Mind Reading" and a GO button

    Think of a number

    Think of any number you like, then tap GO.

  2. Screen showing "And add 8." with an OK button

    Do the math in your head

    Follow each instruction to add or take away a number, and tap OK. At the end, subtract the number you first thought of.

  3. Result screen: "The number you are now thinking of is 7"

    The app reads your mind

    "The number you are now thinking of is…" The app reveals the number in your head.

How the trick works (read after you play)

The app chose every number you added and took away, so it already knows them all. When you subtract the number you first thought of, it cancels out, leaving only the total of the app's numbers. That's why it gets it right whatever number you pick.

Videos

The video above is in English. There is also a Japanese version: Mind-Reading (Japanese)

FAQ

Is Mind-Reading free?

Yes, it's free. No internet connection or account is needed.

Which iPhones does it work on?

It works on iPhones running iOS 15.0 or later, in English, Japanese and Simplified Chinese.

Does it really read my mind?

No. It's a number trick based on simple addition and subtraction. The secret is explained in "How the trick works" on this page.

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