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.
SUPER J8 (Inspired by Jupiter-8*)
$14.99 · In-app purchases
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.
A product spec, screen plans, and build steps for your coding agent.
First kit free with a verified email
Combine features and design from your favorite apps.
Kit ready. Verify your email to download it.
Generating… usually about a minute.
What should your app do differently? Your note travels with the kit so your coding agent builds around your idea.
A product spec, phased build plan, differentiation notes, and screen references.
Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.
Goal: Send a clear invoice after finishing a job.
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.
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.
JavaScript is required to complete mailbox verification.
Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.
Rork plan preview for Super J8 Synth + AUv3: map the core Music workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
Preview ready. Verify your email to reveal and copy the full prompt.
JavaScript is required to complete mailbox verification. Return to this prompt preview.
Affiliate link: CloneChart may earn a commission at no extra cost
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
Assumption to check: Many music synthesizer apps are complicated and hard to navigate.
Validate with people who use this workflow before building.
Hypothesis 2
Assumption to check: Limited sound customization options.
Validate with people who use this workflow before building.
Hypothesis 3
Assumption to check: High learning curve for beginners.
Validate with people who use this workflow before building.
Hypothesis 4
Assumption to check: Performance issues on older devices.
Validate with people who use this workflow before building.
Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.
SUPER J8 (Inspired by Jupiter-8*) Next Level Analog Emulation SUPER J8 delivers lush pads, deep basses, classic keys, and vibrant leads that feel truly alive. Inspired by a LEGENDARY analog synthesizer, SUPER J8 was trained by ethical machine learning and uses advanced DSP. No Generative AI! NO SAMPLES. PURE SYNTH POWER! NEW FEATURES: Oscillator Sync, Cross-Modulation, 2x Oversampling, True Per-Voice Poly Unison, PWM, Analog Voice Modeling, Analog Panning, and Single-Note Polyphony for epic pads and drones that never stop. WHAT PEOPLE ARE SAYING: “I studied a lot of Jupiter-8s. I know how a Jupiter-8 sounds. This is it!” – App/VST Maker “Man I’m already sold after just 1 sound… That’s definitely the Jupiter sound.” – Audio Production (YouTube) “WOW! I'm at 5 minutes in and more than Blown Away” – Jay Zen DEVICE REQUIREMENTS: iPad: 2016 iPad Pro (A9X) or newer (Does not work on iPad Air 2) iPhone: 2018 iPhone XS (A12) or newer (Works on iPhone SE 2020) INSTANT INSPIRATION Explore 700+ hand made presets, a classic step sequencer, dual arpeggiators, analog-style filters, tape delay, reverb, chorus, 3 LFOs, and real-time FX control. Your creativity will never hit a wall "FANTASTIC!" – The GarageBand Guide “I like SUPER J8’s presets BETTER than both the Arturia Jup-8 and Cherry Audio Mercury-8” – Editor, All Things VST “SUPER J8 is a fun, easy-to-use app that everyone should own” – Field Tone Audio WATCH VIDEOS TO HEAR IT IN ACTION: audiokitpro.com/superj8 FEATURES • NEW Sound Engine with advanced DSP • 700+ presets included (more to come) • True Poly Unison with Unison Start Sync • J8-style Cross-Mod plus frequency tracker • 64 voices! Like a Jupiter-64?! Play 8 notes with 8-voice unison • 2x oversampling for more analog-style lows and highs • Awesome Oscillator Sync • PWM engine modeled after vintage hardware behavior • Per-Voice Analog Panning • Single Note Polyphony for notes & unison stacks! • FX: Glorious Reverb based on Sean Costello’s code (Valhalla* Plug-ins), Analog Tape Delay, Crush, and more. • 3 LFOs with 60+ destinations; modulate almost anything (even other LFOs) • MIDI keyboard support plus MIDI Learn • Classic ARP & Vintage-style Step Sequencer • ENV-1 Polarity & 2 ADSR envelopes, just like classic hardware • Juno* style type I & II Chorus • Dual assignable Touch pads for real-time performance control • Jupiter-inspired filter with deep growl WORKS AS A PLUG-IN Use SUPER J8 as an AUv3 instrument in Logic for iPad, GarageBand, AUM, Cubasis, and more. WORKS BY ITSELF • Built-in Record button: capture your synth and FX, then export a WAV file • Control it with a MIDI Keyboard, MIDI Learn to map your controls to the app No other apps required. If you’ve never played a next-generation analog synth emulation, get ready to be inspired! LEARN MORE audiokitpro.com/superj8 * LEGAL NOTICES SUPER J8 is not affiliated with or endorsed by Roland Corporation. “Jupiter-8”, "Juno", and any other referenced trademarks are the property of their respective owners and are used for identification and reference only. SUPER J8 is not an official emulation of any specific instrument. It is an original creation inspired by classic synthesizers, created to celebrate music creation and education. SUPER J8 is not affiliated or endorsed by Valhalla Plugins. We thank Sean Costello for his amazing and generous contributions to open-source code, making this app's beautiful Reverb possible.
Written user reviews are not shown here. Check current App Store reviews >
Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.
Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.
Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.
Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.
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.