O vs CatDays
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
O
This app helps you manage your weight and physical data. It collects information from body fat scales and your smartphone to calculate and store various health metrics.
- Body data collection
- Health data analysis
- Health data storage
- Calculates health indices
- Integrates with body fat scales
Read full descriptionHide full description
In a word: manage the user's weight and physical data Application introduction: APP is divided into three parts: body data collection, health data analysis and health data storage. collect body fat scale’s and smart phone APP data, calculate and store various health index of human's body.
CatDays
Track important dates with a customizable cat companion. Choose from various feline friends to count down to future events or count up days since past milestones. Receive gentle reminders and view your progress with home screen widgets.
- Countdown and count-up modes
- Selectable cat companions
- Customizable reminders
- Home screen widgets
- iCloud synchronization
- Ad-free experience
Read full descriptionHide full description
CatDays is a minimalist countdown and day counter app. Choose a cat for every day that matters. It’ll wait with you for what’s ahead and remember how far you’ve come. Whether you’re looking forward to something in the future or marking a journey already underway, leave the counting to a cat. Every time you open CatDays, it’ll be right there, counting with you. ・Two ways to count: down and up Count down the days until something ahead, or count up the days since something began. Birthdays, trips, anniversaries, exams, or every day since you gave something up—CatDays can keep track of them all. ・The days you’ve lived are worth keeping Every season of anticipation and perseverance deserves to be remembered. One-time countdowns automatically move to Memories after they end. When a chapter comes to a close, you can stop a count-up on the exact day it ended. If you want to keep going, you can bring it back and continue counting anytime. ・A cat of your own Every date can have its own cat. Give it a tap and it’ll strike a new pose and talk to you—every cat has a personality of its own, so each moment together feels a little different. ・Your cat will remind you when it matters When an important day is near or arrives, your cat will send a gentle reminder. It’ll also check in when a count-up reaches a milestone worth marking. Turn reminders on or off and choose your preferred reminder time in Settings—quiet and never intrusive. ・Home Screen widgets put your cat where you’ll always see it Choose from Small and Medium countdown widgets and select the dates you want to display. A Medium widget can also show up to three countdowns at once. Your cat will change poses from time to time, so every glance feels a little different. Tap a widget to jump straight to the details in CatDays—a companion you can see every day. Lock Screen widgets are available too, so you can check the day count without unlocking your iPhone. ・Cat calendar widgets for every day Choose from a variety of cat calendar widgets featuring month, today, and week layouts. Pick your favorite cat and let it keep you company on your Home Screen every day. ・Automatic iCloud sync Your countdown data can sync automatically through iCloud across devices signed in to the same Apple Account, so it stays with you when you switch phones. Your content is stored on your device and in your personal iCloud and is never sent to our servers. ・Clean, calming, and free from distractions No ads, no subscriptions, and no complicated setup. Open CatDays and all you’ll see are your cats and the days that matter to you. 【Meet the Cats】 Included for free: Coco. More cats can be unlocked from the Cat Shop in Settings. Each cat is a one-time purchase and yours to use forever—no subscription required. Want to bring several home at once? Choose a pack for a better value. 【About Purchases】 CatDays is free to download, with all core features included. Additional cat characters are available as one-time purchases with no subscription fees. You can restore previously purchased content anytime from “Restore Purchases” in Settings. Let a cat keep track of the days that matter. Privacy Policy: https://catdays.app/en/privacy/ Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is review sentiment: CatDays at 83% against O's 0%. O's advantage is in-app purchases (none vs 8) and iOS requirement (9.0 vs 17.5). On price, update cadence, ads 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. CatDays sells 8 one-off in-app purchases. O asks for nothing beyond the download.
Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 19, 2026 and October 25, 2026 respectively.
| Parameter | O | CatDays |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.3 (6 ratings) — better |
| Positive reviews | 0.0% of reviews | 83.3% of reviews — better |
| Number of ratings | — | 6 — better |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 9.0 — better | 17.5 |
| Further details — not scored | ||
| Size | 5 MB | 38 MB |
| Age rating | 4+ | 4+ |
| Developer | Shenzhen LINGXI Technology Co., Ltd | Lychee Intelligence Co., Ltd. |
Customer experience
O
CatDays
In-app purchases
O
No in-app purchases
CatDays
- Leo$2.99
- Luna$2.99
- Tofu$2.99
Show 5 moreShow fewer
- Ash$2.99
- Milo$2.99
- Pumpkin$2.99
- Leo & Luna Pack$3.99
- Original Cats Pack$4.99









