Ducker Detective vs OnlyWeekNo.
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Ducker Detective
Easily calculate anyone's age using their birth month and day. This tool can help you verify ages, play harmless pranks, or even predict baby birth dates based on due dates.
- Calculate age from birth month and day
- Verify ages
- Predict baby birth dates
- Play age-related jokes
- Age verification tool
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Do you want to find out people’s age with just the month and day of birth or want to calculate someone’s age using the built-in Age Calculator.You can find out your favorite celebrity or friends’ age also. Check when people are lying about their age. Ducker Detective is a great tool to have. Play a joke on someone and ask them for their month and day of birth and surprise them with their age or with the year they were born. Even more, do you want to predict a baby’s birth based on the doctor's expected birth to get a more accurate prediction.
OnlyWeekNo.
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You can choose the first day of the week, like starting with Sunday or Monday? And you can also choose a rule for the first week of the year. Like ISO 8601, you can choose the first Thursday week as the 1st week, or January 1st as the 1st week, or else.
Screenshots
Verdict
The clearest difference is ads: Ducker Detective at none against OnlyWeekNo.'s shown. On price, update cadence, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Ducker Detective sells 11 in-app purchases, starting at $0.99 per month and OnlyWeekNo. sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on August 18, 2026 and September 17, 2026 respectively.
| Parameter | Ducker Detective | OnlyWeekNo. |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (24 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 24 — better | — |
| Update frequency | Every 2 months | Every 2 months |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 16.0 |
| Further details — not scored | ||
| Size | 100 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | Ducker Detective, LLC | Takenori Kabeya |
In-app purchases
Ducker Detective
- Ad-Free Subscription Monthly$0.991 Month
- GIF subscription monthly$0.991 Month
- Sticker subscription monthly$0.991 Month
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- StickerGIF subscription montly$0.991 Month
- GIF subscription six month$4.996 Months
- Sticker subscription six month$4.996 Months
- StickerGIF Six-Month Plan$4.996 Months
- Ad-Free Subscription Yearly$9.991 Year
- GIF subscription yearly$9.991 Year
- Sticker subscription yearly$9.991 Year
- StickerGIF subscription yearly$9.991 Year
OnlyWeekNo.
- Disable Advertising$0.49
