An MVP to validate an idea quickly
We define the core audience and actions, then build the first app needed to learn from real market response.
iOS · Android cross-platform development
Flutter app development for iOS and Android, from product scope to store launch
We design, build, and launch iOS and Android apps with Flutter, combining thoughtful UX with reliable product engineering.
KEYPLE is a South Korea-based Flutter app development agency working from early MVP validation through complex production features. We build on a shared product foundation and connect release builds, review information, rejection responses, and store launch into one delivery flow.
- 01One product for iOS and Android
- 02Planning, design, and development
- 03Store launch and operational support
Good fit
A strong fit for these projects
If one of these sounds familiar, we can define the specific scope together.
Expanding a web service to mobile
We review the existing product and APIs and reshape them into mobile-first journeys and features.
Products with accounts, payments, or notifications
We build apps that connect authentication, subscriptions, push notifications, content, and service data.
Moving operational workflows to mobile
We turn recurring work such as bookings, field records, and customer management into clear mobile flows.
What we do
Service scope
Choose only what you need or bring the entire product process into one engagement.
- 01Cross-platform iOS and Android development and deployment
- 02Mobile UI/UX design and interactive prototypes
- 03Fast MVP implementation and release
- 04High-performance animation and advanced features
- 05Firebase, backend, and external API integration
- 06App Store and Google Play submission and review support
- 07Stable operation and ongoing maintenance support
Our standard
What finished means to us
We look beyond implemented screens to the standards required for a real launch and operation.
A consistent experience on both platforms
We respect iOS and Android conventions while making the product feel like one coherent brand.
A release scope that can be validated
We prioritize the features needed to reach a real launch instead of building every possible feature at once.
A foundation designed for operation and growth
Data, error handling, and future features are considered so the product remains manageable after launch.
How it works
Our process
We review the outcome of each phase together before moving to the next.
- Step 1
Define the product goal, core users, and MVP scope.
- Step 2
Design the user flow and interface, then validate it with an interactive prototype.
- Step 3
Build the Flutter app and server integrations and test them across representative devices.
- Step 4
Support App Store and Google Play review, launch, and the transition into operation.
Estimate
What shapes the estimate
Every product has a different level of depth, so we review these factors before estimating by phase.
Screens and user journeys
We review screen types, user roles, and the key journeys each user must complete.
Integrated features
Authentication, payments, notifications, maps, APIs, and administration all affect scope.
Planning and design readiness
We account for existing specifications, designs, and the prototype work still required.
Launch and operational support
Store review, analytics, maintenance, and follow-up development are scoped explicitly.
Primary technology
- Flutter
- Dart
- Firebase
- REST API
- App Store
- Google Play
FAQ
Frequently asked questions
Answers to questions teams often ask when outsourcing product development for the first time.
Can I contact you without a finished product specification?
Yes. We can begin with the product goal and primary users, then define the key features, user flow, and practical MVP scope together.
Can you build for both iOS and Android?
Yes. We use Flutter to develop both platforms together and still verify platform-specific behavior such as cameras, permissions, notifications, and payments.
Can you connect an existing server or API?
Yes. We first review the API specification and authentication model, identify any gaps, and then integrate the app with the existing system.
How are Flutter app development schedules and costs determined?
We consider feature complexity, external integrations, design readiness, store launch, and operational scope—not screen count alone—before proposing phases, timing, and cost.
Can you handle App Store and Google Play launch?
Yes. We support developer-account preparation, release builds, store content, submission, rejection analysis, and resubmission. Platform review times vary, so the release plan includes an appropriate buffer.
Project guide
Read before you outsource
Practical criteria that help define scope before comparing schedules and estimates.
App Store and Google Play review times and rejection causes
Plan App Store and Google Play review time, understand common rejection causes, and leave enough room for fixes, resubmission, and a controlled release.
Read insightApp development cost and timeline: seven factors to check
Compare iOS and Android app development estimates across features, design, backend, administration, store launch, and a budget-conscious MVP scope.
Read insightFlutter or native: which approach fits your app?
Compare Flutter and native iOS and Android development across cost, performance, UI, platform features, and long-term operation.
Read insightHow to define the scope and timeline of an MVP app
A practical way to define an MVP hypothesis, essential features, planning, design, development, testing, launch, and post-release scope.
Read insightA checklist for choosing an app development partner
Compare app development proposals across scope, source and account ownership, testing, launch support, maintenance, and communication.
Read insightStart a project
Start a project Your app idea does not need to be fully defined yet.
Tell us where you are and what the product needs to do. We will help define the MVP and the most practical next step.