Seoul · 2026

RiverMountain
Studio

3 Android apps launching on Google Play, 2 PC titles heading to Steam, 5 client services on Kmong.

Real Chatterbury screen: a pixel village at nightChatterbury · PC · Steam / Coming to Steam

Apps & games

Work

Mallowmo key art

PC · Steam · Coming to Steam

Mallowmo

A soft pet that walks on your desktop. Treats, room decor and little diary letters.

Petalhug screen

Android · Google Play · Released · Now in tester release

Petalhug

A routine pet that grows as you finish your tasks — daily to-dos, adventure stories, a room to decorate.

Privacy policy
Grandma’s Phone: Scam or Not? screen

Android · Google Play · Released · Now in tester release

Grandma’s Phone:
Scam or Not?

Grandma gets scam texts and calls — pick her replies and outwit the scammer.

Privacy policy
Past Self screen

Android · Google Play · Released · Now in tester release

Past Self

Grab the bags and escape in 22 seconds. Next round, a copy replays your last run.

Privacy policy

pastself.rivermountain-studio.com · coming soon

Real Chatterbury screen: left side of the village with decor level and viewer residentsReal Chatterbury screen: right side of the village with a donation alert and viewer residents

PC · Steam · Coming to Steam

Chatterbury

A streaming tool where your chat becomes a little village along the bottom of the screen.

Developer tools

App Ship Skills

App Ship Skills terminal report
Terminal report (English output)

Claude Code · Codex · Google Play

9 skills for Claude Code and Codex that find known Google Play problems in your real .aab before you upload. US$29 one-time (planned). Checkout by Creem (Merchant of Record).

View App Ship Skills

Client work

Services available

Menu design for cafes & restaurantsFrom KRW 29,000View on Kmong
Product detail page designFrom KRW 149,000View on Kmong
Custom Flutter app development (Android/iOS)From KRW 1,650,000View on Kmong
PHP security check, update & 30-day careFrom KRW 55,000View on Kmong
App analysis & competitor reportFrom KRW 190,000View on Kmong

Kmong listing pending

  • Small-shop website with booking buttonKmong listing pending
  • KakaoTalk channel AI chatbotKmong listing pending
  • Excel / Google Sheets automationKmong listing pending
  • Toss Payments integrationKmong listing pending
  • Order-merging Google Sheets templateKmong listing pending
  • Small-shop website templateKmong listing pending
  • Build-your-own Kakao AI bot kitKmong listing pending
  • E-book: "Hire one AI employee"Kmong listing pending

How projects run

Consult
Tell us what you need, your timeline and budget.
Quote
We set out the scope and cost.
Build
We build to the agreed scope.
Deliver
We deliver the work for review.

Coming next

In development

TypeOnce screen

Coming soon

TypeOnce

A Chrome text expander. Local only, no account, pay once.

Solo Dev AI Team Ops screen

Coming soon

Solo Dev AI Team Ops

Five skills for people who ship with AI coding agents: handoff, overnight resume, pre-ship UI check, cross-review, i18n QA.

How Many to Win? screen

Coming soon

How Many to Win?

Three daily puzzles: work out how many it takes to win from the clues on screen.

EmoteJelly screenshot

PC · Steam · Coming soon

EmoteJelly

Turn one drawing into 24 Twitch and Discord emotes, with size checks for each platform.

Launchline screen

Coming soon

Launchline

A Framer template for app-launch websites.

Wanya screenshot

Android · Google Play · Coming soon

Wanya

Turn your pet into a look-alike character to live with. Pet it, feed it, walk it, decorate.

Privacy policy

Company

About

RiverMountain Studio is a one-person business in Seoul, Korea. Android apps and games go to Google Play, PC games and a streaming tool to Steam. Developer tools are sold directly (checkout by Creem) and client work is taken through Kmong.

How we work

  • We only show real screens.
  • We collect only the personal data an app needs.
  • We do not inflate numbers or features.

Contact

Contact

Development inquiries

Product and purchase inquiries

Phone

+82 10-7644-3423
Start a project