Questions, bug reports, or feedback are welcome via email.
How to Use
- Type a number with the digit keys
- Tap a unit from the category panel (Mass, Length, Speed, etc.)
- Choose an operator (+/-/×/÷) → number → unit →
= - The result is shown with its unit
FAQ
Q. Why does 3 kg + 5 m show an error?
Mass (kg) and length (m) have different dimensions and cannot be added. The app catches such impossible operations. If you meant multiplication (3 kg × 5 m), tap the "Use ×" suggestion to switch.
Q. Why is 30℃ + 20℃ equal to 50℃?
Temperatures are interpreted as deltas (differences) by default. An opt-in absolute-temperature API is planned for future updates.
Q. Is "banana ≈ 2 ×" for 210 kcal accurate?
It's a rough relatable estimate (using 105 kcal per banana). Don't use this for precise nutritional tracking.
Q. How can I remove ads?
A one-time in-app purchase (¥150) hides banner ads. You can also restore the purchase from the settings screen after switching devices.
Q. I purchased, but ads are still showing / restore fails
Tap "Restore Purchase" in the settings screen. You must be signed in with the same Apple ID / Google account used for the purchase. A weak connection can make restore fail, so try again with a stable network. If it still doesn't work, email support@fujibit.com with the purchase date and the receipt email from the store.
Q. Is "Remove ads" a subscription?
No. It is a one-time purchase with no auto-renewal. Payment is handled by the App Store / Google Play, and we never receive your payment details (see the Privacy Policy).
Q. Does the app use the network?
Calculation works fully offline. Network is used only for ad delivery (Pangle) and for buying or restoring the in-app purchase. The numbers and results you enter are never sent.
Q. What is "Ad settings"?
On first launch, before ads are shown, the App asks on the "About ads" screen whether it may show ads tailored to your interests (personalized ads). "Ad settings" in the settings screen is where you can change that choice later. If you choose "Don't allow", you still see ads, but they are not personalized. Your choice is stored only on your device and can be changed at any time from "Ad settings" in the settings screen. On iOS, the tracking permission (ATT) prompt appears after this question. It is not shown if you have purchased Remove ads. See the Privacy Policy for details.
Reporting Bugs
If you find a bug, please email support@fujibit.com with:
- Device model (e.g., iPhone 15 Pro / Pixel 8)
- OS version (e.g., iOS 17.4 / Android 14)
- App version
- Steps to reproduce