Comparison

CleanAirOptima vs Furigana Keyboard Ruby IME

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

Head to head
About

CleanAirOptima

Features
Read full description

Instant access, wherever you go. Connect smart Clean Air Optima devices, control and monitor them from everywhere in the world only through your smartphone. The CleanAirOptima app allows you to take full control of your indoor air quality. Connect your smart Clean Air Optima devices in a couple of taps: - Control and monitor your smart Clean Air Optima devices using this app from everywhere, either from your office or travelling around the world. All you need is internet access. - Depending on your smart devices, seamlessly monitor the real-time temperature and humidity and set your desired parameter with only a few taps. - Create different rooms in your home, e.g. living room, bedrooms, etc., and specify in which room your smart device is located. In this way, you can keep track of temperature and humidity in different areas in your home. We are working on one of the most important things in the world: Fresh, healthy indoor air. Clean Air Optima International B.V. stands for innovative Clean Air Optima® Air Treatment Technology with healthy indoor air, designed in Germany. Through innovative technology and unique styles, the products of Clean Air Optima fit seamlessly into the individual living ambience. Clean Air Optima Corporate Philosophy. The Clean Air Optima Group ensures its existence through the Satisfaction of its customers. The stated goal is highest Customer satisfaction. Clean Air Optima® products are Certified according to their intended purpose. And for this we constantly monitor the quality of the product, analyze customer problems and recommend appropriate solutions. We offer our customers a high quality customer service: they receive expert advice before and after purchasing our products.

About

Furigana Keyboard Ruby IME

Features
Read full description

Furigana Keyboard Ruby IME is a Japanese furigana keyboard for creating text in Kanji(reading) format as you type. It is built for worksheets, learning materials, reading notes, shared documents, messages, and any place where the reader needs pronunciation next to kanji. Choose a Japanese candidate and insert text with ruby readings without manually adding furigana afterward. For longer passages, paste text into the main app and convert the full passage at once. This furigana keyboard is useful for teachers, parents, Japanese learners, reading notes, and anyone who wants to share easier-to-read Japanese text. It supports both 12-key kana input and romaji input, so you can create kanji with readings in a familiar Japanese keyboard flow. What you get: - 12-key kana input and romaji input - Candidate confirmation as Kanji(reading) - Reading conversion for selected text or recent Japanese text near the cursor - Long text conversion in the main app for pasted passages - Furigana and ruby reading support for worksheets, notes, study materials, and shared documents - No ads, analytics, or in-app purchases - No Full Access required - No typed content sent to external servers Examples: 例えば -> 例(たと)えば 日本語 -> 日本語(にほんご) 食べる -> 食(た)べる Privacy: This keyboard does not require Full Access. Typed content is not sent to external servers, and conversion and learning are processed on device. The app does not include ads or analytics. Note: For existing-text conversion inside other apps, the keyboard extension uses selected text or a limited amount of nearby text before the cursor. To convert a longer passage in one step, use the long text conversion field in the main app. Due to iOS keyboard extension behavior, iOS may switch to the system keyboard in password fields and some special input fields.

Screenshots

CleanAirOptima4 screens
Furigana Keyboard Ruby IME4 screens

Verdict

The call

The clearest difference is price: CleanAirOptima at Free against Furigana Keyboard Ruby IME's $0.49. CleanAirOptima also leads on iOS requirement (12.0 vs 18.0). Furigana Keyboard Ruby IME's advantage is update cadence (every 2 days vs every 17 months). On ads, 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

CostPrice · In-app purchases · Ads · Monetization

CleanAirOptima is free to download; Furigana Keyboard Ruby IME costs $0.49 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

CleanAirOptima ships an update every 17 months, Furigana Keyboard Ruby IME every 2 days. The most recent releases landed on October 6, 2026 and October 17, 2026 respectively.

Scorecard3 real differences · 3 level
CleanAirOptima versus Furigana Keyboard Ruby IME: the parameters behind the verdict, then further details
ParameterCleanAirOptimaFurigana Keyboard Ruby IME
PriceFree — better$0.49
Update frequencyEvery 17 monthsEvery 2 days — better
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPodiPhone, iPad
Requires iOS12.0 — better18.0
Further details — not scored
Size194 MB104 MB
Age rating4+4+
DeveloperClean Air Optima International B.V.HIFUMI

In-app purchases

None

CleanAirOptima

No in-app purchases

None

Furigana Keyboard Ruby IME

No in-app purchases

Questions

Is CleanAirOptima free?
CleanAirOptima is free to download, with no in-app purchases.
Is Furigana Keyboard Ruby IME free?
Furigana Keyboard Ruby IME costs $0.49, with no in-app purchases.
Do CleanAirOptima or Furigana Keyboard Ruby IME have ads?
Neither CleanAirOptima nor Furigana Keyboard Ruby IME shows ads.
Which is updated more often, CleanAirOptima or Furigana Keyboard Ruby IME?
CleanAirOptima ships an update every 17 months, and Furigana Keyboard Ruby IME every 2 days. Most recently, CleanAirOptima was updated on October 6, 2026 and Furigana Keyboard Ruby IME on October 17, 2026.

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