Between Dates Calendar Math vs Dualock
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Between Dates Calendar Math
Calculate the number of days between two dates with a simple interface. Save, recall, sort, and remove date calculations. Add or subtract days from selected dates for quick date projections.
- Calculate days between dates
- Save and recall date calculations
- Sort and remove saved dates
- Add or subtract days
- Copy dates to start/end
- Reset dates to current
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Between Days was written to quickly tell how many days are between two dates. It uses a simple interface to get these answers in the quickest way possible. Underneath the simplicity, Between Days is one of the most feature rich date apps in the app store. Don’t let the simple interface fool you, this app does show a lot of information in a clean and easy to use format. To use the app simply set the start date and end date and it will display the number of days between those two dates. To select which date to edit you can either touch the date you want to change, or press the setting start date/ setting end date button. The selector will automatically change to display the date selected. It will also display the current day of the week showing on the calendar selector. If you would like to save the date for later, simply press the save button on the bottom. To recall a date, or to view saved dates press the view dates button on the bottom. Once you are at the list of dates you can sort or remove them. You can also press on a date to use it as the current date, or press done to return to your previous dates. There are also add and subtract buttons. This is useful if you need to find what the date is before or after a certain number of days, month or years. The copy to end date/copy to start date button will set both the start date and end date to the selected date. The reset button will set the beginning and end date to the current date, but will leave your saved dates alone. I hope you enjoy this app and find it useful! If you have any questions or comments send me an e-mail at Don.Espe@gmail.com Please rate this app so I know if there is enough interest to develop new features for it.
Dualock
This app securely stores your notes by splitting them into two encrypted parts, stored separately. Access requires authentication from two specified SNS accounts, ensuring your data remains private and inaccessible to others.
- Two-part encrypted note storage
- Separate cloud storage for each part
- Dual SNS account authentication
- No password required
- Secure and private data handling
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Write your note. Leave Dualock keep it safe in the cloud. We do not use password, because password is not safe enough and hard to remember. Every note you saved here will be splited into two part. Both the parts will encrypted separately and saved separately, using a pair of SNS account you specified. To unlock your note, both accounts is needed. Only you know the pair and the order of the pair. It's safe. Even I don't know how to crack it.
Screenshots
Verdict
The clearest difference is ratings volume: Between Dates Calendar Math at 42 against Dualock's 1. Between Dates Calendar Math also leads on device support (4 vs 2) and price ($0.99 vs $1.99). Dualock's advantage is rating (5.0 vs 4.8). On update cadence, ads, in-app purchases and monetization model 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
Between Dates Calendar Math costs $0.99 and Dualock $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Dualock holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Between Dates Calendar Math has 42 ratings behind it against 1, so its average is the more settled of the two.
Both ship on a similar rhythm, roughly every 4 months. The most recent releases landed on October 23, 2026 and October 20, 2026 respectively.
| Parameter | Between Dates Calendar Math | Dualock |
|---|---|---|
| Price | $0.99 — better | $1.99 |
| Rating | 4.8 (42 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 42 — better | 1 |
| Update frequency | Every 4 months | Every 4 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone, iPod |
| Requires iOS | 13.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 26 MB |
| Age rating | 4+ | 4+ |
| Developer | Ducky Planet LLC | Gear Zero Network Inc. |
Customer experience
Between Dates Calendar Math
Dualock
In-app purchases
Between Dates Calendar Math
No in-app purchases
Dualock
No in-app purchases
Questions
Is Between Dates Calendar Math free?
Is Dualock free?
Which has better reviews, Between Dates Calendar Math or Dualock?
Do Between Dates Calendar Math or Dualock have ads?
Which is updated more often, Between Dates Calendar Math or Dualock?
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