RapidExposure vs i IChing
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RapidExposure
This app transforms your iPhone into a professional exposure meter. It continuously measures light and displays ISO, F-stop, and shutter speed values without needing to take a photo. You can adjust these settings and lock the exposure to save a reference image with the calculated values.
- Real-time exposure measurement
- Adjustable ISO, F-stop, and shutter speed
- Exposure lock and reference value saving
- History of saved exposure values
- Tap-to-adjust exposure on preview
- Detailed 1/3 step display mode
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This app will turn iPhone into exposure meter for cameras. It can continuously measure exposure value and indicate the information without releasing the shutter. It allows you to recalculate and indicate the shutter speed together with other ISO values and F values even during the measurement. The measurement is interrupted by the save button, and then write a row exposure value which iPhone automatically set into the image that iPhone had been taking, The image with the row exposure value is saved as a sample and displayed. It also displays the exposure value that the user has set. You can see the saved images on a list of images in the history window. You can adjust and rock the exposure on the tapped point of the preview screen. The exposure rock can be cancelled by the 'Auto' button. The shutter sound can be reduced by the volume button. However, it becomes the normal volume if it is set mute. At first the app puts high priority on ISO and F in exposure calculation. Under the exposure measurement, it indicates variable aperture stops (F-number) at a fixed shutter speed when you manually change the shutter speeds. Or, when you manually change the aperture stops (F-numbers), it indicates variable shutter speeds at a fixed aperture stop. If you change the ISO value, shutter speed or F-value changes depending on the mode at the time. The range of ISO vales, F values and shutter speeds are as follows. (In the new version, detail display mode is added in which F,ISO,SS values are changed by 1/3 step) ISO vales: "25","50","100","200","400","800","1600","3200","6400","12800","25600","51200" F values: "F0.7", "F1", "F1.4", "F2", "F2.8","F4", "F5.6", "F8", "F11", "F16","F22", "F32" shutter speeds: "60","30","15","8","4","2","1","1/2","1/4","1/8","1/15","1/30","1/60","1/125","1/250","1/500","1/1000","1/2000","1/4000","1/8000" ******** How to use: (1) Immediately after start-up, this application starts the exposure calculation automatically and it displays the values of ISO, F and SS in the wheel. (2) Exposure is recalculated in accordance with the subject that is reflected in the camera, the value of the SS will change accordingly. When you point the camera toward bright, the value of SS is reduced. Turning the camera to darker, the value of the SS will increase. (3) If you change the value of the ISO in the wheel, the value of the SS will change accordingly. Changing the value of F in the same manner, the value of the SS will change. Further, changing the value of the SS, the value of F will change. (4) If you tap the "Save" button, the exposure value displayed at that time is locked and a photo is taken. A reference exposure value that iPhone camera set to itself is written in the photo. (The reference value is different from that displayed in the wheel. It is not possible to set exposure value in the wheel to iPhone camera itself.) (5) If you tap the "measure" button, it restarts the exposure calculation and re-displays the values of ISO, F and SS. (6) If you tap the "History" button, the History window appears and the contents saved are listed. They are save date and time , photos and the exposure values you had set by the wheel when you save. (7) You can enlarge the photo by tapping it. (8) It changes to delete mode when you tap the "trash", delete mark appears in the photo that you tap. If you tap "Done", photos marked for deletion will be deleted. (9) **** This app uses OSS:AQGridView(Copyright(c) 2010-2011, Kobo Inc.) NOTE: However this app calculates ISO vale, F value and shutter speed based on the photos taken with the built-in camera, we are not able to guarantee the accuracy of these values.
i IChing
This app offers authentic I Ching divination using a faithful digital recreation of the traditional yarrow stalk method. It provides over 250,000 characters of content, including original texts and Wilhelm commentary, to guide important life decisions.
- Authentic yarrow stalk divination
- 250,000+ characters of content
- Complete Wilhelm commentary
- Ad-free divination experience
- Browse all 64 hexagrams
- Automatic reading history
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Authentic I Ching divination, completely free. Experience traditional yarrow stalk divination faithfully recreated digitally, with 250,000+ characters of content including original texts and Wilhelm commentary. Confucius, Carl Jung, and Zhuge Liang all turned to this ancient Chinese oracle. Let 3,000 years of wisdom guide your important life decisions. ▼ KEY FEATURES 【Authentic Yarrow Stalk Divination】 Traditional I Ching divination method faithfully recreated with digital algorithms. Get authentic Yi Jing readings anytime, anywhere. 【250,000+ Characters of Content】 • Original Chinese classical texts • Clear English translations • Complete Wilhelm commentary with detailed explanations Unmatched depth for understanding the true essence of I Ching. 【Ad-free Divination Experience】 No ads during your reading. Focus on gaining deep insights in a calm, undisturbed environment. 【Browse All 64 Hexagrams】 Explore every hexagram anytime, even without divination. Perfect for I Ching study and research. 【Automatic Reading History】 All readings and notes saved automatically. Reflect on life's crossroads and track your personal growth. ▼ WHO IS THIS FOR? • Facing major life decisions — career, relationships, moving • Seeking guidance on work, business, or personal matters • Looking to deepen self-understanding and inner reflection • Interested in Eastern philosophy and I Ching studies • Wanting a free, authentic divination app without gimmicks ▼ WHAT IS THE I CHING? The I Ching, or "Book of Changes," is an ancient Chinese text revealing the laws of life and the universe through 64 hexagrams. Beyond simple fortune-telling, it's a powerful tool for self-understanding and decision-making, still used worldwide today. ▼ DOWNLOAD FREE NOW Bring ancient Chinese wisdom into your daily life. Receive messages that can transform your journey.
Screenshots
Verdict
The clearest difference is review sentiment: i IChing at 100% against RapidExposure's 38%. i IChing also leads on price (Free vs $0.99) and update cadence (every 10 days vs every 2 months). RapidExposure's advantage is in-app purchases (none vs 1) and iOS requirement (12.0 vs 16.6). On 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
i IChing is free to download; RapidExposure costs $0.99 up front. i IChing sells 1 one-off in-app purchase. RapidExposure asks for nothing beyond the download.
RapidExposure ships an update every 2 months, i IChing every 10 days. The most recent releases landed on October 19, 2026 and October 10, 2026 respectively.
| Parameter | RapidExposure | i IChing |
|---|---|---|
| Price | $0.99 | Free — better |
| Positive reviews | 37.5% of reviews | 100.0% of reviews — better |
| Update frequency | Every 2 months | Every 10 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 12.0 — better | 16.6 |
| Further details — not scored | ||
| Size | 9 MB | 101 MB |
| Age rating | 4+ | 4+ |
| Developer | HIROFUMI MARUO | QOOQ inc. |
Customer experience
RapidExposure
i IChing
In-app purchases
RapidExposure
No in-app purchases
i IChing
- Premium$7.99
Questions
Is RapidExposure free?
Is i IChing free?
Do RapidExposure or i IChing have ads?
Which is updated more often, RapidExposure or i IChing?
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