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.
Koala is the ultimate pocket-sized sampler
$4.99 · In-app purchases
Evidence scope: #85 is the current overall US Paid chart position. 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.
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Combine features and design from your favorite apps.
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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.
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Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.
Rork plan preview for Koala Sampler • Beat Maker: map the core Music workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
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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: Limited audio editing features compared to professional apps.
Validate with people who use this workflow before building.
Hypothesis 2
Assumption to check: Difficult to manage multiple samples at once.
Validate with people who use this workflow before building.
Hypothesis 3
Assumption to check: Lack of social sharing options.
Validate with people who use this workflow before building.
Hypothesis 4
Assumption to check: No support for cloud storage.
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.
Koala is the ultimate pocket-sized sampler. Record anything with your phone's mic or load your own sounds. Use Koala to create beats with those samples, add effects and create a track! Koala's super intuitive interface helps you make a track in a flash - there is no brake pedal. You can also resample the output of the app back into the input, through the effects, so the sonic possibilities are endless. Koala's design focuses totally on making the music-making process instant, keeping you in the flow and keeping it fun, not getting bogged down by pages of parameters and micro-editing. "Been putting that $4 koala sampler to good use lately. Undeniably great tool that puts some of these expensive beat boxes to shame. A must cop." -- flying lotus, twitter * Record up to 64 different samples with your mic * Transform your voice or any other sound with 16 superb built-in fx * Load your own samples * Choose from one of 250 built-in sounds * Resample the output of the app back into a new sample * Export loops or entire tracks as professional quality WAV files * Direct export to Ableton Live Set * Copy/paste or merge sequences just by dragging them * Create beats with the high-resolution sequencer * Import samples from the Files app or even from videos * Keyboard mode lets you play chromatically or one of 9 scales * Quantize, add swing to get the right feel * Normal/One-shot/Loop/Reverse playback of samples * 6 Choke groups * Attack, release and tone adjustable on each sample * Mute/Solo controls and note repeat * Add any (or all) of the 16 effects to the entire mix * AUv3 compatible - use in GarageBand, Logic, Cubasis etc etc * MIDI controllable - play your samples on a keyboard, map the effects to knobs * Jam with others over WiFi with Ableton Link * Free copy of Ableton Live Lite included * AudioShare compatible * Use AI to separate samples into individual instruments (drums, bass, vocals and other) * Set your own background image and choose from a growing list of background visual FX 8 Built-in Microphone FX: * More Bass * More Treble * Fuzz * Robot * Reverb * Octave up * Octave down * Synthesizer 16 Built-in DJ Mix FX: * Bit-crusher * Pitch-shift * Comb filter * Ring modulator * Reverb * Stutter * Gate * Resonant High/Low Pass Filters * Cutter * Reverse * Dub * Tempo Delay * Talkbox * VibroFlange * Dirty * Compressor Features included in SAMURAI In-App Purchase * Pro-quality Timestretch (5 modes: Modern, Retro, Beats, Re-pitch and Cyclic) * Piano roll editor * Auto-chop (auto, equal, and lazy chop) * 3 Band EQ * Pocket operator sync out * Quokka Synth - powerhouse polyphonic synthesizer * MIDI Out - control external MIDI hardware with Koala's sequencer * Chopper - multimodal sample chopping instrument Features included in MIXER In-App Purchase * Mix your beats professionally with a 4 channel mixer + main bus * Route any sample to any channel * Mute/solo, faders and accurate metering on every channel * 5 effect slots per channel * 29 high-quality effects - compressors, filters, phasers and more, with new effects to come * Host AUv3 plugins - both audio effects and instruments
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.