Expanding an existing web service into Toss
We assess the current product and APIs and define what can be reused and what should change for a mini-app journey.
Toss Mini App · Apps-in-Toss SDK · launch support
Services that open instantly inside Toss
We build mini apps that run directly inside Toss without a separate installation, with focused journeys shaped around the service goal.
KEYPLE supports both the conversion of existing web services and new games or utility products. We build for Apps-in-Toss policies and runtime constraints and stay involved through sandbox testing, review feedback, and launch.
- 01Runs in Toss without installation
- 02Apps-in-Toss SDK and API integration
- 03Review and launch support
Launched mini apps
Projects you can open directly in Toss
Open each case study to review the work and launch the live Toss mini app.
01Watermelon Balloon: Merge Puzzle
An iOS and Android casual merge puzzle built with Flutter, Flame, and Forge2D, featuring physics, combos, high s...
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02Ducky Ducky
An iOS and Android survival game with touch movement, fish collection, a growing duckling flock, time rewards, a...
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03HEXTRI: Triangle Puzzle
An iOS and Android casual puzzle built with Flutter and Flame, featuring triangular grids, hexagon rules, score ...
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04Puzzle Link
An iOS and Android tile-link puzzle featuring two-turn path rules, Classic and Endless modes, combos, saved game...
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05Memory Link: Memory Puzzle
An iOS and Android memory puzzle with Challenge and Training modes, progress statistics, combos, and a global le...
View project and open mini appGood fit
A strong fit for these projects
If one of these sounds familiar, we can define the specific scope together.
Short, repeatable utility services
Records, calculations, recommendations, and schedules become concise tools users can open at the moment of need.
Casual games that need low-friction entry
We build games that play instantly and consider sharing, return visits, and measurable engagement.
An MVP validated with Toss users
We prioritize the core action and define a measurable release scope for learning from real usage.
What we do
Service scope
Choose only what you need or bring the entire product process into one engagement.
- 01Mini-app product planning and user-flow design
- 02Apps-in-Toss WebView or React Native development
- 03Required Apps-in-Toss SDK and API integrations
- 04Share links, deep links, and acquisition paths
- 05Toss sandbox and production-environment testing
- 06Review submission, launch, and update support
Our standard
What finished means to us
We look beyond implemented screens to the standards required for a real launch and operation.
A complete experience shaped for Toss
The primary task can be completed naturally inside the mini app without unnecessary external navigation.
A clear path from sharing to action
Deep links connect the service home and relevant screens, and external shares communicate a clear destination.
A foundation that remains operable after launch
Error monitoring, analytics, APIs, and the update workflow are designed for continuous improvement.
How it works
Our process
We review the outcome of each phase together before moving to the next.
- Step 1
Define the service goal and the core action the mini app must support.
- Step 2
Design the journey and UI around Apps-in-Toss policies and TDS guidance.
- Step 3
Implement SDK and API features and validate them in the sandbox and the Toss app.
- Step 4
Submit for review, address feedback, and support launch and operation.
Estimate
What shapes the estimate
Every product has a different level of depth, so we review these factors before estimating by phase.
New build or existing-service conversion
Scope changes depending on whether current web screens and APIs can be reused.
SDK and external integrations
Login, user data, payments, sharing, advertising, and proprietary APIs are reviewed.
Screen and content scale
Screen types, data structures, game assets, and operational content all affect effort.
Launch and operational support
Review responses, analytics, error monitoring, and follow-up updates are scoped explicitly.
Primary technology
- Apps-in-Toss SDK
- React
- TypeScript
- WebView
- Toss App Sandbox
- Firebase · API
FAQ
Frequently asked questions
Answers to questions teams often ask when outsourcing product development for the first time.
Can an existing web service be moved into Apps-in-Toss?
Yes. We review the current screens and API architecture, then separate reusable parts from the changes required for the Toss mini-app environment.
Does a Toss mini app require a separate installation?
Toss users open the mini app directly inside the Toss app. External share links can also lead users to the appropriate mini-app entry path.
Can you integrate Toss login and sharing?
When the service needs them, we review the available Apps-in-Toss SDKs and APIs and connect features such as identity, user information, sharing, and deep links.
Can you support the launch review?
Yes. We check the required items before submission, implement requested changes, and support the project through release.
How are schedule and cost determined?
We consider whether the product is new, the scale of screens and features, SDK and API integrations, design and content readiness, and review and operational support.
Project guide
Read before you outsource
Practical criteria that help define scope before comparing schedules and estimates.
From Apps-in-Toss development to mini-app launch
A practical overview of service scope, SDK integrations, sandbox testing, review submission, and launch when preparing a Toss mini app.
Read insightStart a project
Start a project Build a service that starts instantly inside Toss.
Share the current product URL or the features you want to build. We will outline feasibility, scope, and the path to launch.