Quick quizzes for the guitar fretboard and chords, with the question beside its answers
Does Fretalus work on iPhone Duo?
Yes, since version 1.4.2, and seen in iPhone Duo simulator screenshots: on the open Duo, the question and fretboard sit beside the answer buttons.
- Simulator verifiedIndividuation Labs, the developer, in a submission to FoldHunt on October 27, 2026, and on the Fretalus website, with App Store screenshots from the iPhone Duo simulator. The App Store seller is Individuation Labs LLC. The release notes for version 1.4.2 (released October 24, 2026) say that on an unfolded iPhone Duo the question sits beside its answers.
Adapted for the fold
- Open · Inner display
The question beside its answers
Open, each quiz puts the question and the fretboard or chord chart on one side and the answer buttons on the other; in Play mode, the prompt sits beside the board.
- Closed · Outer display
Everything fits, closed
Closed, the Chords and Ear quizzes tighten their layouts so every answer and chart fits on the cover.
About Fretalus
Fretalus, by Individuation Labs, helps you memorize the guitar or bass fretboard and basic chords with quick quizzes. Play the answer on your instrument and the app listens, or tap it. Quizzes cover notes, chords, the CAGED system and ear training. It costs $1.99 and runs on iPhone, iPad and Android.
On an unfolded iPhone Duo each question sits beside its answers, the fretboard or chord chart on one side and the buttons on the other, as the developer’s screenshots from the simulator show. Closed, the Chords and Ear quizzes are tightened to fit the cover.
Evidence reviews
What we checked, when, and what the evidence establishes. Each record preserves the support label at that check.
· Simulator screenshots reviewed
Simulator verified · iphone-duo
Looked at the website's captioned App Store screenshot of the open display, 1426 × 1003 pixels, with the 9:41 status ring: a Notes question, What note is this?, with the fretboard and a marked fret on the left and four note names to pick from on the right. The site's other Duo screenshots show Play mode and a chord diagram beside chord names.
Poses shown: Open. These are observations of the evidence, not a test of every interaction.
App version: 1.4.2. Environment: iPhone Duo simulator.
App Store screenshots with no Xcode version; the cover isn't shown. No build was tested.
View reviewed evidence ↗
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Is this your app?
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Sources: Fretalus website (individuation.dev) · Fretalus on the App Store (apps.apple.com)
More for iPhone Duo
RectoVerso: Flashcards
Simon Pinkas
Flashcards whose answer arrives as you open the phone: stop as soon as you know it
Simulator verified: Simon Pinkas, the developer, in a submission to FoldHunt on October 22, 2026, describing the closed, opening, half-folded, open and Split View layouts. The press kit has screenshots set in Apple's iPhone Duo artwork. RectoVerso came out on the App Store on October 23, 2026, at version 1.0.2: its description has an On iPhone Duo section, and the release notes mention opening iPhone Duo to reveal a figure's labels and Stats showing its chart beside the summary on the open, upright phone.
- Closed
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- Open
- Split View
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Simulator verified: DM Solutions and Development, the developer, in a submission to FoldHunt on October 15, 2026, saying it will be ready on launch day, with a recording of version 1.0 in the iPhone Duo simulator on YouTube. The app is on the App Store as Facing Pages: Learn Languages (version 1.0.2, first released October 19, 2026), and its description has a "MADE FOR IPHONE DUO" section.
- Closed
- Open
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Lumessa
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Daily vocabulary as two pages: the word on the left, each lesson step on the right
Simulator verified: Lumessa Limited, the developer, in a submission to FoldHunt on October 22, 2026, pointing to iPhone Duo screenshots on its press page, captioned as captured in Apple's iPhone Duo simulator. The release notes for version 1.2.0 (released October 21, 2026) say that when you open the phone, Lumessa spreads across both pages, with the word on the left and each step on the right.
- Open
- Closed