Thoughtful apps for everyday life.

Blue Danube Studio is an independent app studio in New York. We make simple, private apps that help people learn, build good habits, and stay close to the people who matter, a little each day.

No accounts to create, no ads, no tracking. Just well-made tools that respect your time and your attention.

Independent studioBased in New YorkPrivate by designBuilt with our testers

Our apps

Each app does one thing well. They're made for real routines, a few minutes on the bus or before bed, and they're shaped by the people who use them.

Mendocles icon

Mendocles

a flashcard for every word you meet
Android · in testing on Google Play

Mendocles helps you remember the words you learn, in one language or several at once. Add the words you meet in class, in books or on your travels, and a smart schedule brings each one back just before you'd forget it.

  • 18 languages, with optional starter words
  • Spaced repetition that adapts to you
  • Recall cards for building speaking
  • Pictures and spoken pronunciation
  • Import your own word lists
  • Your words stay on your device
Visit mendocles.comJoin the Android beta
Hibikind icon

Hibikind

perfectly imperfect
Android · in testing on Google Play

Hibikind is a habit tracker for people who've tried habit trackers and quit after breaking a streak. Set goals daily, on chosen days, weekly, twice a month or monthly, and check them off as you go. Missing a day doesn't wreck your progress.

  • Forgiveness coins, earned through streaks
  • Cover a missed goal after the fact
  • Honest stats: done versus covered
  • Weekly mood check-ins
  • Small earned treats
  • Kind, but still accountable
Join the Android beta
F.A.C.T. icon

F.A.C.T.

Friends and Contacts Tracker
Android · in testing on Google Play

F.A.C.T. helps you be the friend who remembers. It reminds you who you haven't talked to in a while and what you meant to ask them about, and it keeps the birthdays and dates that matter to the people in your life. Everything stays on your phone.

  • Reminders for who to reach out to
  • "Ask about next time" notes
  • Birthdays and important dates
  • Favorites, gift ideas and details you'd forget
  • Groups for friends, family and work
  • Private, offline, no account

Join the beta in two quick steps, using the same Google account as your Android phone:

  1. Join the tester groupThen click "Join group".
  2. Become a tester and installOpens F.A.C.T. on Google Play.
Look up icon

Look up

a gentle nudge to rest your eyes
Computer · runs in your web browser

Look up reminds you to lift your eyes from the screen every 20 minutes, or however often you like. A friendly cloud keeps you company while you work, then hops up with a spoken reminder and an idea for a quick break.

Look up is a browser app for your computer. Open it in Chrome, Edge, Safari or Firefox on a laptop or desktop and keep the tab open while you work. It isn't made for phones.

  • Reminders every 20 to 60 minutes, or your own
  • Spoken alerts in the voice you choose
  • Break ideas: stretch, walk, refill your water
  • Optional back-to-work reminder
  • A floating mini window (Chrome and Edge)
  • Nothing to install, no account
Open Look up
Slippery Slope icon

Slippery Slope

what would you really do? only you need to know.
Android · in testing on Google Play

Slippery Slope is an endless game of everyday dilemmas for grown-ups. Each card is a quick scenario at work, with friends, on a date or next door, with two choices: the honest one and the tempting one. Swipe to decide, and keep going.

  • 1,400+ dilemmas that don't repeat
  • 20 themes, from Work and Dating to Pets, Commute, Spouses and Exes
  • Coins for every decision unlock new themes
  • A Daily Dilemma and a timed Gut check mode
  • Unfiltered (18+): harder dilemmas, tough questions
  • A private profile of where you hold firm
  • Your answers never leave your phone
  • In English, Spanish, German and French

Join the beta in two quick steps, using the same Google account as your Android phone:

  1. Join the tester groupThen click "Join group".
  2. Become a tester and installOpens Slippery Slope on Google Play.

Our approach

A few principles guide every app we make.

01

Private by default

Your data belongs to you. Our apps keep what you create on your own device. There are no accounts to sign up for, and nothing is sold, shared or used for advertising.

02

Kind, not pushy

No guilt trips, no manipulative streaks, no endless notifications. We design for steady progress and for showing up imperfectly, because that's how real habits and real learning last.

03

Simple to use

Clear screens, plain words, and features that earn their place. If something needs a manual, we haven't finished designing it.

04

Honest and lasting

No ads and no tracking, with fair, upfront pricing when there's anything to pay for. We build things we'd want to use ourselves, for years.

Built with our testers

Every app starts small and grows with the people using it. Our testers try each version, tell us what works and what doesn't, and their feedback shapes every update.

When testers asked for both Brazilian and European Portuguese, Mendocles added both. When they wanted to choose their own words instead of a fixed list, starter words became optional and word-list import became available in every language, at any time. That's the kind of studio we want to be.

You try the appJoin a beta through Google Play and use it in your everyday routine.
You tell us what you thinkReply to an email anytime: what helped, what confused you, what's missing.
We improve itFeedback goes into the next version, and you get the update automatically.

About the name

One river, many places, and a little brighter than it really is.

The Danube flows nearly 2,900 kilometers from Germany's Black Forest to the Black Sea, through ten countries and past more capital cities than any other river. Along the way it crosses as many languages as borders.

"The Blue Danube" is also Johann Strauss's famous waltz, written in 1866 to lift Vienna's spirits after a hard year. The river is rarely blue, though. An old saying holds that only people in love see it that way.

We like both ideas: one river connecting many places, and a way of seeing everyday life a little more brightly. Our logo, an arched window looking out on the water, is that view.

Become a tester

Help shape our apps before anyone else. Testing is free, open worldwide, and takes only a few minutes a day. Pick an app below to join its beta.

Test Mendocles Test Hibikind Test F.A.C.T. Test Slippery Slope

Contact

We read every message and reply personally.

General questions

Business, press and partnerships

bluedanubestudio@gmail.com

Mendocles support

Help, feedback and beta invitations

mendocles@gmail.com

Hibikind support

Help, feedback and beta invitations

hibikind@gmail.com

F.A.C.T., Look up and Slippery Slope

Help, feedback and beta invitations

bluedanubestudio@gmail.com