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.
Designed by sports scientists and coaches
$9.99 · 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.
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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 My Sprint: map the core Sports 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 functionality compared to competitors
Validate with people who use this workflow before building.
Hypothesis 2
Assumption to check: Poor user reviews regarding UI/UX
Validate with people who use this workflow before building.
Hypothesis 3
Assumption to check: Subscription model confusion
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.
Designed by sports scientists and coaches. Scientifically validated (publication in review in a high-impact journal). The only app that accurately calculates the complete power-force-velocity profile using the groundbreaking Samozino et al.´s method (published in 2015). My Sprint is the first app scientifically developed to measure the individual sprint mechanical outputs (force, velocity, power, effectiveness) of athletes. Innovative design, validated by sports scientists, My Sprint is as reliable as a 4000$ radar plus PC system. Scientifically approved! Sprint running, power output and forward acceleration are a key combination of performance in many sports activities. Determining individual Force–Velocity profile, maximal power and mechanical effectiveness during sprint propulsion is of great interest for coaches, sport practitioners, or physiotherapists. What makes you fast? Their opinion about My Sprint: - Dr. Samozino: “One of our main interests is to make accessible to sport practitioners the scientific evaluations we do in our labs with very specific devices. The simple method on which My Sprint is based was developed in this sense to test the sprint mechanical capabilities in field condition. The results of the validation of the method in comparison to force plate measurements were better than those we expected! And the validity of the data obtained with My Sprint is in the same extent… but with an impressive simplicity!” - Pr. Morin: “When we developed our 2015 simple method, we found it was a great achievement to measure sprint acceleration mechanics with a very high concurrent validity compared to the gold standard force plate measurements. My Sprint takes things to another level, since it allows accurate measurements with just an iPhone!” My Sprint calculates Power-Force-Velocity profile and measures the individual sprint mechanical outputs (force, velocity, power, effectiveness) of athletes using the camera on your iPhone, iPod touch or iPad. It was specially designed to take advantage of the extraordinary 120-240fps camera of the iPhone 5s, iPhone 6 and iPhone 6s. You just need to perform an all-out 40 m sprint and mark the track with a reference system marks located at 5, 10, 15, 20, 30 and 40 meters and you only need six visible vertical markers (like thin poles) at these markers to record the time between markers. After that My Sprint does the computations and calculates athlete´s mechanical capabilities. FEATURES: - Accurate measurement of the split times over a sprint acceleration. Scientifically validated! - Calculation the Power-Force-Velocity profile using the innovative Samozino et al.´s method. You can therefore know the athlete’s mechanical capabilities that determine the entire sprint acceleration performance. These properties are integrative and encompass all the mechanisms involved in the total external force produced during each lower limb extension and the ability to orient it effectively onto the ground. - Record amazing slow motion videos up to 240fps (iPhone 5s, iPhone 6 and iPhone 6s) and analyse in a frame-by-frame mode as well as import videos from your camera roll. - Multi-user. You can create as many users as your need with My Sprint. You can assign each user to a team for a higher ease of use. - Performance follow-up. You can record as many sprints as you want for each user created and analyze performance through a competitive season. Note: My Sprint was scientifically validated using an iPhone 6, and it uses the slow motion video recording on the iPhone 5s, iPhone 6 and iPhone 6s. On other devices, the measurements are less accurate slow motion video recording feature is not available. A SPRINT ACCELERATION MECHANICS LAB IN YOUR POCKET!
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.