Costan vs DDays
Price, ratings, monetisation and update history for both apps, side by side โ with what reviewers say about each.
Costan
Learn everyday greetings in 14 languages to connect with people worldwide. This app promotes a peaceful, borderless world through simple, friendly communication.
- Learn greetings in 14 languages
- Promotes cross-cultural communication
- Focuses on everyday phrases
- Aims for a peaceful world
- Simple and friendly interface
Read full descriptionHide full description
In Costan, you also Cosmopolitan from today! From "Time" and "Hello" First. Acquire the voice of the 14 languages โโof everyday greeting to dodge with a smile. A peaceful world without boundaries in heart!
DDays
Track important upcoming events with timely notifications. View countdowns directly on your home screen and lock screen widgets.
- D-day tracking
- Advance notifications
- Home screen widget
- Lock screen widget
- Live activity display
Read full descriptionHide full description
Meet Simple D-day! You can check notifications and live-activity 24 hours in advance. Check D-Day through the Home screen, the lock screen widget!
Screenshots
Verdict
The clearest difference is update cadence: DDays at every 2 weeks against Costan's every 6 weeks. Costan's advantage is device support (3 vs 1) and iOS requirement (15.6 vs 17.0). On price, review sentiment, ads and in-app purchases there is nothing between them.
Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Costan ships an update every 6 weeks, DDays every 2 weeks. The most recent releases landed on September 9, 2026 and June 5, 2026 respectively.
| Parameter | Costan | DDays |
|---|---|---|
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Update frequency | Every 6 weeks | Every 2 weeks โ better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod โ better | iPhone |
| Requires iOS | 15.6 โ better | 17.0 |
| Further details โ not scored | ||
| Size | 7 MB | 5 MB |
| Age rating | 4+ | 4+ |
| Developer | Shinichi Aokawa | Lee Jaeho |
Customer experience
Costan
DDays
In-app purchases
Costan
No in-app purchases
DDays
No in-app purchases
