App Overview

Judder Haptics icon

Judder Haptics

Craig Trim · Developer Tools

Judder is the best haptic editor on iOS: a workbench for developers who want to design feedback by feel, not by guesswork

$0.99

PRICE
$0.99
No in-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
5.0
2 ratings · Top 5%

Evidence scope: No current overall US chart position is available. Category-chart positions shown in discovery are a separate scope. Revenue is a directional model estimate, not verified earnings.

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Build Kit

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A product spec, screen plans, and build steps for your coding agent.

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What's included15 files

A product spec, phased build plan, differentiation notes, and screen references.

  • START_HERE
  • AGENTS
  • EVIDENCE
  • SPEC
  • BUILD_PLAN
  • DIFFERENTIATION
  • skills/
  • screens/
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Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.

Feature spec

Goal: Send a clear invoice after finishing a job.

  • Add a client, line items, a due date, and payment instructions.
  • Preview the total before exporting a PDF.
  • Keep an editable draft if export fails.

Screen plan

Invoice editor: Client at the top, editable line items in the middle, total and preview action at the bottom.

States: Empty draft, validation errors beside each field, exporting, and a retry action that preserves the draft.

Differentiate and validate

Hypothesis: Contractors need faster repeat invoices more than more templates.

First experiment: Test duplicating a previous job with five contractors. Watch where they hesitate before expanding the feature set.

The full kit adds a phased build plan, evidence notes, tool prompts, and implementation guidance. It is a plan for your coding agent, not a finished app.

Usage: Mechanics are fair game; never reuse the original name, branding, assets, or verbatim copy.

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Quick prompt

> SELECT BUILD PLATFORM:

Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.

// RORK SYSTEM PROMPT
Rork plan preview for Judder Haptics: map the core Developer Tools workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
            

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Opportunities

AI-GENERATED OPPORTUNITY HYPOTHESES

These are generated suggestions, not verified review quotations. Check current App Store reviews and speak with users before treating a possible gap as a requirement.

Hypothesis 1

Allow users to customize more parameters such as frequency and waveforms.

Assumption to check: Limited customization options for haptic feedback patterns

Validate with people who use this workflow before building.

Hypothesis 2

Implement a sharing feature to allow users to export and share their patterns.

Assumption to check: No option to share patterns with others

Validate with people who use this workflow before building.

Hypothesis 3

Add a rating or feedback system for users to evaluate patterns.

Assumption to check: Lack of user feedback on patterns

Validate with people who use this workflow before building.

Hypothesis 4

Create an onboarding experience to guide users through the app features.

Assumption to check: No tutorial or onboarding for new users

Validate with people who use this workflow before building.

App evidence

Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.

App Store description

Judder is the best haptic editor on iOS: a workbench for developers who want to design feedback by feel, not by guesswork. Build tactile patterns on the iPhone your users will hold, see every event on a shared timeline, and export the result as AHAP JSON or paste-ready Swift. Haptics are temporal. One event at full intensity is already the hardware maximum, so stronger feedback comes from rhythm, density, overlap, envelope and context. Most haptic feedback is one buzz. Judder builds the whole chain: transient hits, continuous beds and dense bursts on one axis, overlapping wherever you want them to. Scrub parameters, replay the pattern, and learn what changes the feel before you put it in your app. START FROM REAL MOMENTS Practical recipes for the moments an iOS app actually has: alerts, incoming calls, long press feedback, checkout success, scrubber texture, toggles and sustained physical effects. Open a pattern and adjust intensity, sharpness, duration, gaps, attack, release, burst spacing, loop behaviour and audio support, then keep the version that feels right. SEE THE WHOLE PATTERN The editor shows a haptic lane over an audio lane with a live playhead, so you can see whether a burst sits on top of a bed, whether an audio file covers the whole pattern, and where loop seams will land. A burst is not one row in a list. It is every impulse it expands into, drawn at the real spacing. Add one of the bundled beds or import your own short audio file, trim it, audition it, and use it alongside the haptic to shape the result. TAKE IT WITH YOU Copy AHAP JSON for a resource file, copy Swift for a constant in your project, or share the files out of the app. The export keeps authored structure where possible, validates the resolved timeline, and includes the audio sidecar when a custom bed needs to travel with the AHAP. KNOW YOUR HARDWARE The Engine tab reports haptic hardware support, audio-haptic support, device identity, audio-session behaviour and global playback calibration. On the Simulator, Judder is honest about what cannot be felt. On device, it is a compact lab for getting tactile feedback right before it ships. Judder is built for developers and design teams who already know haptics matter and need a better way to choose what they should feel like. No account. No backend. No network dependency. Just timeline, playback, tuning and export.

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Screenshots

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Build scope

Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.

Define the first version

Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.

Set boundaries

Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.

Check the hard parts

Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.

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BUILD KIT DIFFICULTY
Advanced

From the Build Kit assessment.

A reliable timeline needs an agreed scope and a technical check. Ask your agent to estimate the phases in BUILD_PLAN.md after that review.