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.
App Overview
Drops: Language Learning Games
Join over 50 million people who use Drops for free language lessons
Free · In-app purchases
PRICE
Free
In-app purchases
BUSINESS MODEL
Freemium
No overall Grossing estimate available
RATING
★ 4.7
71,276 ratings · Top 15%
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.
Build your own version
Build Kit
Make this idea yours
A product spec, screen plans, and build steps for your coding agent.
First kit free with a verified email
Add to a Remix
Combine features and design from your favorite apps.
Kit ready. Verify your email to download it.
Generating… usually about a minute.
Make it yours Optional
What should your app do differently? Your note travels with the kit so your coding agent builds around your idea.
What's included17 files
A product spec, phased build plan, differentiation notes, and screen references.
- START_HERE
- AGENTS
- EVIDENCE
- SPEC
- BUILD_PLAN
- DIFFERENTIATION
- skills/
- screens/
Preview a sample Build Kit No email needed
Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.
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.
JavaScript is required to complete mailbox verification.
Free quick prompt For a smaller starting point
Quick prompt
Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.
// RORK SYSTEM PROMPT
Rork plan preview for Drops: Language Learning Games: map the core Education 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.
Continue in Rork >
Affiliate link: CloneChart may earn a commission at no extra cost
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
Introduce more diverse games and challenges.
Assumption to check: Limited game variety may lead to boredom.
Validate with people who use this workflow before building.
Hypothesis 2
Implement a comprehensive progress dashboard with detailed analytics.
Assumption to check: Difficulty in tracking progress due to lack of detailed stats.
Validate with people who use this workflow before building.
Hypothesis 3
Design a more user-friendly upgrade path with value propositions.
Assumption to check: In-app purchase prompts can be intrusive.
Validate with people who use this workflow before building.
Hypothesis 4
Include social features like leaderboards or friends challenges.
Assumption to check: Lack of community interaction features.
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
Join over 50 million people who use Drops for free language lessons. It’s fast, fun, and easy! Practice vocabulary in Spanish, Japanese, French, Korean, Chinese, German, English. Discover 55+ different new languages with Drops! Learn new languages while playing games. You can become fluent, learn vocabulary and common phrases in Hebrew, Arabic, Russian, and Hindi. Set goals, unlock achievements, and get rewards! • Become fluent in a foreign language with this language learning app • Learn to read characters and scripts from different alphabets like Korean, Japanese, Chinese, Hebrew, Arabic, Russian, and Hindi • Custom illustrations for each vocabulary word makes it easy to remember • From beginner to expert levels, grow your foreign language vocabulary • A professionally curated vocabulary list with more than 3,000 words and phrases • Game-like language lessons that make language learning fun and effective • Level up! Track your progress and get rewards • Professional voice artists and sound design with correct dialect pronunciations • Learn to speak languages like Arabic, Chinese (Mandarin), English (British), English (American), French, German, Icelandic, Italian, Japanese, Korean, Portuguese (European), Russian, Spanish (Mexican), Spanish (European), Tagalog, Ainu, Arabic (Egyptian), American Sign Language (ASL), Basque, Bosnian, Cantonese, Catalan, Chti, Croatian, Danish, Dutch, Esperanto, Estonian, Finnish, Galician, Greek, Greenlandic, Hawaiian, Hebrew, Hindi, Hungarian, Igbo, Indonesian, Irish, Maori, Norwegian, Persian, Polish, Portuguese (Brazilian), Romanian, Samoan, Sanskrit, Serbian, Swahili, Swedish, Swiss German, Thai, Turkish, Ukrainian, Vietnamese, Welsh, and even Yoruba! "By focusing on visually appealing games and vocab, Drops aims to lower the barrier preventing users from exploring a new language and, ultimately, accessing the social and economic benefits knowing that language may provide." - TechCrunch We are featured by CNET, Forbes, VentureBeat and many other places too! Try Drops Premium with a 7 day free trial. Download the app to learn about different membership options, and register to learn all about exclusive discounts. Payment will be charged to your iTunes Account at confirmation of Drops premium. Afterwards your account will be charged for renewal within 24-hours prior to the end of the current period. Auto-renewal may be turned off at any time by going to your settings in the iTunes Store after purchase. You can cancel your subscription anytime, and you won't be charged in the next billing cycle. Privacy Policy and Terms of Use: http://languagedrops.com/privacypolicy.html
Written user reviews are not shown here. Check current App Store reviews >
Screenshots
< Scroll to see more >
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.
SUGGESTED BUILD STACK
React Native
Expo
Supabase
React Navigation
React Native Reanimated
React Native Chart Kit
BUILD KIT DIFFICULTY
Intermediate
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.
