DONNOKAvailable for iPhone · iPad · Android
The same money.
A changing value.
From the day you set money aside to today — a display that shows how prices have changed what it can buy.
Free download · In-app purchases
A closer look at the app.
Record an amount and a date, then explore how purchasing power changes over time.
Actual iPhone app screens · Sample funds · Calculations are estimates based on assumptions
A simple record.
A slow view.
Just an amount and a date
Enter the money you want to follow and when you saved it. No bank connection, no sign-up — it stays on your device.
Measured against prices
Estimated purchasing power uses the Korean Consumer Price Index (CPI). It is not your actual bank balance.
How we calculateRight on your home screen
Add a widget to your iPhone or Android home screen, or your iPhone lock screen. The operating system decides when it refreshes.
User guide
Displayed amounts are estimates based on economic data and calculation assumptions, not actual balances or guaranteed investment returns. The app checks for Korean CPI updates when activated. Check data dates and update status in the app. iOS · iPadOS 16.4 or later. Download the Android app on Google Play.
Notes on money
Explore pay, prices and purchasing power with worked examples.
Tired of daily expense tracking? A lighter way to observe saved money
Try DONNOK with a sample amount, then record one fund. Use a retro money display or home screen widget to observe estimated purchasing power without a daily expense diary.
Customize a retro money display with FLIP, NIXIE and a clock
Turn DONNOK into a retro desk display. Compare real FLIP and NIXIE screens, then combine a custom title, 24-hour clock and lower information fields.
Customize a money widget on iPhone or Android without changing the app theme
Keep FLIP in the app and choose a different DONNOK widget theme. Explore decimals, cumulative change and calculation time, plus iPhone and Android display differences.