Calculator : Formula & History

This calculator app features an easy-to-read display for both your equations and history. Calculations are automatically saved to a history list, allowing you to easily review them later.

The list appears right above the input field, so you can check it at a glance without switching screens. This helps minimize mistakes and makes editing your history seamless.

Perfect for calculating shopping totals, expenses, travel costs, and more.

[Main Features]

📝 See Your Formula and History at a Glance

See your current equation in real-time and check the answer instantly.
When you press equals (=), the equation and result are automatically added to your history.

Simply scroll up or down to see your complete calculation overview at any time.
No more taking notes or switching screens.

🔗 "Reference" Function with Linked Answers

Tap any answer in your history to insert that value into your current equation.
If the original equation's result changes, any calculation referencing it will automatically update.

(Example: Reference the answer from "100+100=200". If you later change the original to "100+200=300", the referenced calculation will automatically update to use 300.)

This lets you use the app like a simple spreadsheet.

✍️ Add Memos to Know What You Calculated

You can attach a memo while entering an equation.
It's also possible to add memos to your history items later.

By noting things like "Lunch" or "Client Travel," you'll always remember the purpose of each calculation.

🔍 Powerful Memo Search

Search for keywords in your memos across all your calculation lists.
Memo your calculations with tags like "July Trip," and you can instantly find all related entries later.

🧮 Instant Total with One Tap

Calculate the sum of all items in your current history with a single tap.
Perfect for finding the grand total of your shopping or expenses.

✅ Check Function for a Smarter History

Check items in your history to see a real-time subtotal of only the selected entries.
You can also batch-delete multiple items at once, making it easy to clean up your list.

This turns your history from a simple log into an interactive tool.

[Useful Customization Features]

⌨️ Create Shortcuts for Frequent Calculations

Freely add custom keys like "+8%" (for tax) or "-20%" (for discounts) to the toolbar above the keyboard.

You can add an unlimited number of custom keys.
This saves you from typing the same numbers repeatedly and speeds up your workflow.

🎨 Customize the Look and Feel

Supports an eye-friendly Dark Mode.

You can also fully customize the app's theme color, font size, and even the number of decimal places displayed, making it perfectly suited to your preferences.

📚 Multiple Lists for Different Purposes

Create and switch between multiple lists for different needs, such as "Work," "Personal," or "Trip Budget."
Keep your calculations organized and separate.

📅 Show Timestamps in History

Display the date and time for each entry to know exactly when you made a calculation.
This can be enabled in Settings.

[Other Useful Features]

🗑️ Trash Can for Peace of Mind: Accidentally deleted a list? You can restore it from the trash for up to 30 days.

📲 Share & Duplicate: Share your calculation history with other apps, or duplicate a list to start a new calculation.