Comparison

DI9FLOW vs AstroStacker

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

Head to head
About

DI9FLOW

Features
Read full description

DI9FLOW App is a collection of entertainment and security in one of the App. Our new hardware devices have the capabilities of sending out WiFi and connecting WiFi. It realizes two functions of super long distance control and direct connection control. The new device is equipped with a microphone so that it can monitor the surrounding sound. Our product prototype is an aircraft, and we can use App for flight control when using direct control. It will be a flying toy. When configuring our device to connect the router at home, we can monitor the safety of the family through the Internet, taking pictures, videos, listening and other functions. It will be a security device.

About

AstroStacker

Enhance your night sky photos by stacking multiple exposures into a single, detailed image. This app automatically aligns stars, reduces noise, and offers tools to refine your astrophotography results directly on your iPhone or iPad.

Highlights
  • Stack multiple night sky photos
  • Automatic star alignment
  • Noise reduction for clearer images
  • Advanced editing tools
  • Support for calibration frames (Pro)
  • On-device processing
Features
Read full description

Stack your night-sky photos into one cleaner, more detailed image, right on your iPhone or iPad. Astrophotography stacking combines many exposures of the same sky. Astro Stacker finds the stars in every frame, lines them up and combines them, so random noise falls away and faint stars, the Milky Way and deep-sky targets come through. HOW IT WORKS 1. Take several separate photos of the same patch of sky from a tripod or stable surface. 2. Import them from Photos or Files into a Deep Sky Studio project. 3. Pick a stack mode and tap Stack. 4. Finish the result with Auto Stretch, styles and colour tools, then save or export. THREE SIMPLE STACK MODES - Quick: averages every frame for a fast first look. - Quality (default): rejects outliers such as plane and satellite trails, and leaves out the weakest frames. - Max Detail: the slowest and most selective mode, with finer alignment. AUTOMATIC STAR ALIGNMENT Stars are detected and matched in every frame, with sub-pixel alignment and a quality check for each frame. Stacking needs clear stars in your photos to line them up. CALIBRATION FRAMES (PRO) Add darks, flats, dark-flats and bias frames to correct hot pixels, thermal noise, vignetting and dust. Astro Stacker sorts frames by file name and exposure, so files named "dark" or "flat" are picked up for you. FINISH IN THE SAME APP - Auto Stretch to bring faint signal into view - Gradient removal for light pollution and uneven skies - Local contrast, vibrance, levels and per-channel colour balance - Styles: Natural, Nebula Pop, Cosmic Drama and Scientific, each with a strength slider - Before-and-after comparison - Quick Enhance for a single photo you've already taken FILES IN AND OUT - Import: photos from your library on Free; camera RAW, Apple ProRAW and FITS on Pro - Export: JPG, PNG, TIFF and FITS, with 16-bit export on Pro ON-DEVICE Stacking and editing run on your iPhone or iPad. You don't need a computer, and your source frames are not uploaded to stack them. An optional account backs up finished results. FREE AND PRO Free: 1 free stack with up to 10 light frames, and 3 saved results. Pro: unlimited frames and stacks, RAW, ProRAW and FITS import, calibration frames, 16-bit export and unlimited history. Choose monthly, annual or a one-time lifetime purchase. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period, and you can manage them in your App Store account settings. GOOD TO KNOW - Moon, planet and solar stacking (Planet Lab) is coming soon. Today's stacking needs stars to align on. - Colour FITS files from one-shot-colour cameras are not debayered yet. - Star-trail stacking isn't supported, because every stack is aligned on the stars. Guides to capturing and stacking: https://astrostacker.co/guides Privacy Policy: https://astrostacker.co/privacy Terms of Use: https://astrostacker.co/terms Apple Standard EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

DI9FLOW3 screens
AstroStacker4 screens

Verdict

The call

The clearest difference is in-app purchases: DI9FLOW at none against AstroStacker's 3. DI9FLOW also leads on iOS requirement (15.6 vs 17.0). AstroStacker's advantage is update cadence (every 2 weeks vs monthly). On price, 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. AstroStacker sells 3 in-app purchases, starting at $12.99 per month. DI9FLOW asks for nothing beyond the download.

UpkeepUpdate frequency

DI9FLOW ships an update monthly, AstroStacker every 2 weeks. The most recent releases landed on November 6, 2026 and November 12, 2026 respectively.

Scorecard3 real differences · 7 level
DI9FLOW versus AstroStacker: the parameters behind the verdict, then further details
ParameterDI9FLOWAstroStacker
PriceFreeFree
Rating—1.1 (7 ratings) — better
Positive reviews—0.0% of reviews
Number of ratings—7 — better
Update frequencyMonthlyEvery 2 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Freemium
DevicesiPhone, iPodiPhone, iPad
Requires iOS15.6 — better17.0
Further details — not scored
Size14 MB17 MB
Age rating4+4+
Developer芝青 蔡Ahmed Al-Mahmud

In-app purchases

None

DI9FLOW

No in-app purchases

3 purchases

AstroStacker

Subscriptions2
  • AstroStacker app3 Days trial$12.991 Month
  • AstroStacker app3 Days trial$99.991 Year
One-time1
  • AstroStacker app$219.00

Questions

Is DI9FLOW free?
DI9FLOW is free to download, with no in-app purchases.
Is AstroStacker free?
AstroStacker is free to download, with in-app purchases available.
Do DI9FLOW or AstroStacker have ads?
Neither DI9FLOW nor AstroStacker shows ads.
Which is updated more often, DI9FLOW or AstroStacker?
DI9FLOW ships an update monthly, and AstroStacker every 2 weeks. Most recently, DI9FLOW was updated on November 6, 2026 and AstroStacker on November 12, 2026.

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