Comparison

OCEANUS Connected vs CITIZEN Eco

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

OCEANUS Connected

This app connects your Bluetooth-enabled CASIO watch to your iPhone, enabling various Mobile Link functions. It simplifies watch operations and allows data transfer to the new CASIO WATCHES app. Requires iOS 14 or later and 'Always' location service permission.

Highlights
  • Bluetooth watch connectivity
  • Mobile Link functions
  • Simplified watch operations
  • User data transfer
  • Location services for time accuracy
Features
Read full description

Important - Please Read Request to Transfer to the CASIO WATCHES App (Support Termination Notification) The functionality of this app will be transferred to the new watch app, CASIO WATCHES. By updating to version 3.0, users of this app will be able to transfer their user data to CASIO WATCHES via this app. While we understand this may be inconvenient for some users, we ask that you transfer your data across, and continue using CASIO WATCHES in place of this app. ●Description This is the basic application for connecting and communicating with a Bluetooth(R) v4.0 enabled CASIO watch. Pairing your watch with an iPhone enables use of a variety of different Mobile Link functions that greatly enhance the iPhone experience. The OCEANUS Connected app also simplifies certain watch operations by letting you perform them on your phone screen. Visit the website below for details. http://www.casio-watches.com/oceanus/ We recommend using OCEANUS Connected on the following operating systems. Operation is not guaranteed for any operating system not listed below. Even if an operating system has been confirmed as compatible, software updates or display specifications may prevent proper display and/or operation. ⋅ iOS 14 or later. Applicable Watches: OCW-G2000, OCW-S4000, OCW-T3000, OCW-T200, OCW-S5000, OCW-P2000, OCW-T4000 *Some watches unavailable in your region may be displayed in the application. This application uses location information to obtain accurate time. For "Location Service" in iPhone privacy settings, please "Always". If it is not "Always", the application will not work properly. Continued use of GPS running in the background can dramatically decrease battery life.

About

CITIZEN Eco

This app connects your smartphone to compatible watches, allowing you to sync time, set alarms, and receive notifications for calls and messages. It also features world time settings and a light level indicator for the watch's power source.

Highlights
  • Automatic time synchronization
  • World time settings
  • Call and message notifications
  • Customizable alarms
  • Light level indicator
  • Smartphone search function
  • Link loss alerts
Features
Read full description

*Important Notice Thank you for using Citizen products. As of 12/31/2027, we will no longer provide service for dedicated apps for some models and functions used in conjunction with the apps. For details, see this link. https://www.citizenwatch-global.com/support/im/smartwatch.html Overview This is the official app for linking your smartphone with CITIZEN Bluetooth® watches. The app, which works with iPhone, enables you to set the time and the alarm for your watch, and to receive alerts for incoming calls, mails and texts. With the CITIZEN Bluetooth Watch, you get to enjoy an exquisite analogue watch that tells the accurate time wherever you are plus the great convenience of a smartphone link. CITIZEN Bluetooth features CITIZEN’s proprietary light-powered technology Eco-Drive. Eco-Drive eliminates the need to replace batteries or recharge via cable. Features 1. Time Sync Get the right time, all the time. When you connect with your smartphone, the time on your watch automatically updates to the current time (smartphone time). 2. World Time Get the time in any city around the world. Just touch the world map inside the app to set your watch to the locations time (world time). 3. Call Notification Find out when you get a call. The watch emits a sound or rotates the hands to let you know when you get a call. A filter function enables you to specify which callers will trigger alerts. 4. Message Notification Find out when you get a mail, text or SNS notification. The watch emits a sound or rotates the hands to let you know when a new e-mail or SNS notification has arrived. You can also select the apps for which you wish to receive notification alerts. 5. Alarm Set your alarm from your smartphone. You can set up to 3 alarms at one time. By setting your watch alarm using the smartphone app. The alarm can be set for different times and/or different days of the week. 6. Light Level Indicator See how much light—and power—your dial is getting. Find out how much power your watch is generating by tracking the light it’s exposed to on a daily, weekly or monthly basis. This unique function reflects CITIZEN’s status as a pioneer of light-powered technology. 7. Smartphone Search Find your smartphone easily. Misplaced your smartphone? Not a problem. Use your watch to locate your phone by having it emit a sound to indicate its whereabouts. (Range limitations apply.) 8. Link Loss Alert Get alerted when you’ve forgotten your smartphone somewhere. The watch emits a sound or rotates the hands to let you know when the link between your smartphone and your watch is broken. This app requires iOS 11.2 or later. Notifications have the options of 15 different original sounds, exclusively prepared for the W410 mode About Eco-Drive: Eco-Drive is a CITIZEN proprietary light-powered technology which eliminates the need for replacing batteries. Eco-Drive generates power from any kind of light—from sunlight to dim light—to drive the watch, and stores the surplus on a rechargeable cell. On a single full charge it can run for up to six months in total darkness*. For more details, click here. http://www.citizenwatch-global.com/technologies/index.html#eco-drive * Some models run for less than six months.

Screenshots

OCEANUS Connected2 screens
CITIZEN Eco4 screens

Verdict

The call

The clearest difference is review sentiment: OCEANUS Connected at 43% against CITIZEN Eco's 0%. OCEANUS Connected also leads on update cadence (every 2 months vs every 5 months) and iOS requirement (11.0 vs 15.6). On price, 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

OCEANUS Connected ships an update every 2 months, CITIZEN Eco every 5 months. The most recent releases landed on November 5, 2026 and November 4, 2026 respectively.

Scorecard3 real differences · 7 level
OCEANUS Connected versus CITIZEN Eco: the parameters behind the verdict, then further details
ParameterOCEANUS ConnectedCITIZEN Eco
PriceFreeFree
Rating4.7 (120 ratings) — better—
Positive reviews43.5% of reviews — better0.0% of reviews
Number of ratings120 — better—
Update frequencyEvery 2 months — betterEvery 5 months
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPod
Requires iOS11.0 — better15.6
Further details — not scored
Size222 MB67 MB
Age rating4+4+
DeveloperCASIO COMPUTER CO., LTD.CITIZEN WATCH CO.,LTD

Customer experience

OCEANUS Connected

All ratings120 ratings
Positive91.7%
Neutral2.5%
Negative5.8%
Written reviews46 reviews
Positive43.5%
Neutral13.0%
Negative43.5%

CITIZEN Eco

Written reviews6 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

OCEANUS Connected

No in-app purchases

None

CITIZEN Eco

No in-app purchases

Questions

Is OCEANUS Connected free?
OCEANUS Connected is free to download, with no in-app purchases.
Is CITIZEN Eco free?
CITIZEN Eco is free to download, with no in-app purchases.
Do OCEANUS Connected or CITIZEN Eco have ads?
Neither OCEANUS Connected nor CITIZEN Eco shows ads.
Which is updated more often, OCEANUS Connected or CITIZEN Eco?
OCEANUS Connected ships an update every 2 months, and CITIZEN Eco every 5 months. Most recently, OCEANUS Connected was updated on November 5, 2026 and CITIZEN Eco on November 4, 2026.

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