# AstroStacker: Stack the Sky — Astrophotography on iPhone > Mobile astrophotography stacking and editing app for detailed night sky images. (iPhone/iPad app by Ahmed Al-Mahmud.) - Source: https://appshunter.io/ios/app/astrostacker-stack-the-sky/id6753679598 (this page in markdown: same URL + `.md`) - Developer: [Ahmed Al-Mahmud](https://appshunter.io/developer/1844352476) - Category: Photo & Video - Price: Free with in-app purchases - Rating: 1.10/5 from 7 App Store ratings · 11 written reviews indexed - Age rating: 4+ - Requires: iOS 17.0 · 17 MB - Languages: American English, French (France), German (Germany), Italian, Japanese, Korean, Brazilian Portuguese, Chinese (Simplified, China), European Spanish - Released: 2025-10-07 - Data updated: 2026-11-12 - Monetization: freemium - User reviews in markdown: https://appshunter.io/ios/app/astrostacker-stack-the-sky/id6753679598/reviews.md ## What is AstroStacker? 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/ ## Key features - Stack multiple night sky photos - Automatic star alignment - Noise reduction for clearer images - Advanced editing tools - Support for calibration frames (Pro) - On-device processing ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | AstroStacker app | $12.99 | per month | | AstroStacker app | $99.99 | per year | **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | AstroStacker app | $219.00 | one-time | ## Is AstroStacker safe? Not enough ratings yet to assess AstroStacker. ## Is AstroStacker legit? AstroStacker: Stack the Sky appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for AstroStacker is 73 out of 100 points across 7 verification signals from App Store and developer data. ## Recent user reviews (10 of 11) All indexed reviews: https://appshunter.io/ios/app/astrostacker-stack-the-sky/id6753679598/reviews.md ### 1/5 — Doesn’t allow you to save *2026-10-28* Shows a stacked image i could work with but wont save. The developer stated it would be fixed after the latest update, that was not the case. You still can’t save the stacked photo in the free version. Oh well, deleting. **Developer response:** Sorry, you were right. In that version, saving could look like it did nothing, especially after editing the photo. The update that came out after your review fixes this, and the free plan saves your stacked photo to Photos. If it still won't save for you, email support@astrostacker.app and I'll sort it out. Rhu, Astro Stacker ### 1/5 — Terrible. *2026-10-22* This app won’t even process RAW or jpg photos. Gave me an error code for both. Not even worth downloading. **Developer response:** Sorry about that. Since your review we've fixed several problems with bringing photos in. JPG and HEIC photos stack on the free plan; RAW files need Pro. If a JPG still shows an error, email the error code to support@astrostacker.app and I'll look into it myself. Rhu, Astro Stacker ### 1/5 — Doesn’t work at all *2026-08-24* I try to put an image and it says not enough stars found, so I put a image with more stars and it says not enough stars found, also there is no configuration setting like it says on the crash screen **Developer response:** Sorry about that. The app now tries again at a more sensitive setting before it says there aren't enough stars. You're right that the message sent you to a setting that isn't there; we've rewritten it, and that's in the next update. Tip: sharp photos of a clear, dark sky, taken one after another from the same spot, work best. Rhu, Astro Stacker ### 1/5 — Would be great if it worked *2026-06-17* This app has the potential to be the best for astrophotography and image stacking if it actually stacked your images without crashing. There are a multitude of settings and adjustments that you could make that you wouldn’t find anywhere else and it’s layout is great but anytime I attempt to stack any number of images (even two on the lowest settings), every time it gets to 65% it automatically crashes. I’m not willing to jeopardize any money on upgrading my free subscription to find out if it works then I doubt it. Make it work and it’d be well worth the money though. **Developer response:** Sorry about the crashes. Since your review we rebuilt how stacking works, and the crash partway through a stack is fixed. If the app gets closed mid-stack, it now carries on where it stopped. Please update and give it another go. If it still crashes, email support@astrostacker.app with your iPhone model and I'll help you myself. You can try it on the free plan without paying anything. Rhu, Astro Stacker ### 2/5 — nope *2026-05-12* App makes it so you sorta have to pick a paid option to do anything. tapping ‘free’ when a paid/free choice pops up does not work. I paid the seven bucks. It isnt worth the seven bucks I paid for it. Now I have to wait for it to show up on my itunes account or whatever to request a refund. It isnt siril. It isnt pixinsight. It couldnt produce results with known good input. skip it. would have rated it one start except nobody takes a one start serious. **Developer response:** Sorry about this. You can now keep using the free plan without paying, and stacking is much more reliable than when you tried it. If you'd like your money back, you can ask Apple at reportaproblem.apple.com. Rhu, Astro Stacker ### 1/5 — ? *2026-03-15* Please help I tried a lot and all the app does is crash. If this is fixed then that would be amazing, since I REALLY want a mobile stacking app. PLEASE fix this!! **Developer response:** Sorry about the crashes. Since your review we rebuilt how stacking works, and the crash partway through a stack is fixed. If the app gets closed mid-stack, it now carries on where it stopped. Please update and give it another go. If it still crashes, email support@astrostacker.app with your iPhone model and I'll help you myself. Rhu, Astro Stacker ### 3/5 — ooh ooh ahh ahh *2026-02-09* all these are the same person reviewing I balance it **Developer response:** Thanks for stopping by! If you try the app, I'd love to hear what you think. Rhu, Astro Stacker ### 1/5 — Crash. Crash. Crash *2026-01-21* Simply crashes every time you try to stack anything. Garbage. **Developer response:** Sorry about the crashes. Since your review we rebuilt how stacking works, and the crash partway through a stack is fixed. If the app gets closed mid-stack, it now carries on where it stopped. Please update and give it another go. If it still crashes, email support@astrostacker.app with your iPhone model and I'll help you myself. Rhu, Astro Stacker ### 1/5 — All it does is crash. *2025-12-16* I had to put one star to leave a review but all this app does is crash. **Developer response:** Sorry about the crashes. Since your review we rebuilt how stacking works, and the crash partway through a stack is fixed. If the app gets closed mid-stack, it now carries on where it stopped. Please update and give it another go. If it still crashes, email support@astrostacker.app with your iPhone model and I'll help you myself. Rhu, Astro Stacker ### 3/5 — Good app, needs polishing *2025-12-14* Ive dealt with it since ios 26 came out and well it is a decent app, it needs more polishing on the merging of the pictures and the alignment, sometimes it closes when theres a lot of pictures but it is acceptable since there’s no other apps like these Its a decent one, just needs some polishing! **Developer response:** Thank you for sticking with it. Since your review, blending and lining up photos is much better, and the crashes with lots of photos are fixed. I hope it feels more polished now. Rhu, Astro Stacker ## Frequently asked questions about AstroStacker ### What is AstroStacker used for? AstroStacker is used to combine multiple photos of the night sky into a single, cleaner, and more detailed image. It helps reduce noise and bring out faint celestial objects like stars and the Milky Way. ### How does AstroStacker work? You take several photos of the same sky area from a stable surface, import them into the app, select a stacking mode, and tap 'Stack'. The app then aligns the stars and combines the images. ### What are the different stacking modes in AstroStacker? AstroStacker offers three modes: 'Quick' for a fast average, 'Quality' (default) which rejects outliers and weaker frames, and 'Max Detail' for the most selective and finest alignment. ### Can I use calibration frames with AstroStacker? Yes, calibration frames like darks, flats, dark-flats, and bias frames are available in the Pro version. These help correct issues like hot pixels, thermal noise, and vignetting. ### What file formats can I import and export with AstroStacker? The free version imports photos from your library. The Pro version supports RAW, Apple ProRAW, and FITS import, and exports JPG, PNG, TIFF, and FITS, with 16-bit export available. ### Is AstroStacker available on Android? Based on the provided data, AstroStacker is supported on iPhone and iPad, indicating it is an iOS-exclusive application. ### What is the user rating for AstroStacker? AstroStacker has a user rating of 1.1 stars based on 7 ratings. ### How much does AstroStacker Pro cost? AstroStacker Pro offers monthly ($12.99), annual ($99.99), and a one-time lifetime purchase ($219.00) option. Subscriptions include a 3-day free trial. ## Version history (last 5 releases) ### 2.1.1 — 2026-11-10 New in 2.1.1 Photos go where you put them: the button you press (Lights, Darks, Flats or Bias) decides the group, so night photos no longer end up with your darks. When a stack can't find enough stars, the app now tells you why in plain words: photos sent through another app, a sky that's too bright, a shutter that's too fast, or only some photos with stars. A Contact us button sends us a note if it keeps happening. Each calibration type has its own icon. Thank you for every review. These fixes came from them. Clear skies. ### 2.1.0 — 2026-11-09 New in 2.1.0 A new look. The app now wears the night: midnight, cream and starlight gold. Home opens on a single noisy frame and clears into stars, the way stacking does. Tonight's moon: the real phase sits in the sky on Home, with a word on whether it's a good night to shoot. Your stacks now rest on the pile of frames that made them, with how much less noise the stack has than one photo. Drafts show as a grainy frame until they're stacked. The stacking ring clears from noise to stars as it works. Plan changes: the free plan now includes 1 stack a month. When a free trial of Pro is on offer, the plans screen shows it, so you can try everything first. Tip: stack 10 or more photos for a clean result. With only one photo checked, the app now tells you. Clear skies. ### 2.0.9 — 2026-10-31 Satellite and plane trails that cross only one frame are now rejected when stacking, so they no longer leave a faint line in your result. Saving an edit now sticks: the edited image becomes the project's result, so the Result screen, Share and Export all show what you saved. Clear skies. ### 2.0.8 — 2026-10-27 A redesigned AstroStacker. • Enhance, rebuilt: Style, Light and Colour tabs keep your photo front and centre, and Save is one tap away. • Styles you control: every look now starts at a natural, balanced strength. Use the new Strength slider to dial it down — or push it further. • A clearer stacking screen: a progress ring with a time estimate that only counts down, four simple steps, and buttons that respond instantly while it works. • Smarter colour: skies no longer turn magenta when a style is applied. • Fixes: Stop now really stops (and doesn't use up a free stack), the import sheet closes itself when your photos are in, and the notification prompt no longer interrupts a stack. AstroStacker is now available in German, Spanish, French, Italian, Japanese, Korean, Portuguese and Simplified Chinese, alongside English. Clear skies. ### 2.0.7 — 2026-10-16 A redesigned AstroStacker. • Enhance, rebuilt: Style, Light and Colour tabs keep your photo front and centre, and Save is one tap away. • Styles you control: every look now starts at a natural, balanced strength. Use the new Strength slider to dial it down — or push it further. • A clearer stacking screen: a progress ring with a time estimate that only counts down, four simple steps, and buttons that respond instantly while it works. • Smarter colour: skies no longer turn magenta when a style is applied. • Fixes: Stop now really stops (and doesn't use up a free stack), the import sheet closes itself when your photos are in, and the notification prompt no longer interrupts a stack. AstroStacker is now available in German, Spanish, French, Italian, Japanese, Korean, Portuguese and Simplified Chinese, alongside English. Clear skies. ## Apps similar to AstroStacker | App | Rating | Price | Category | | --- | --- | --- | --- | | [AstroFinish](https://appshunter.io/ios/app/astrofinish/id6763904575) | 4.9 (8) | Free | Photo & Video | | [PlanetEdit - Simple and Quick](https://appshunter.io/ios/app/planetedit-simple-and-quick/id6758052019) | 4.5 (2) | Free | Photo & Video | | [Eagle Image Stacker](https://appshunter.io/ios/app/eagle-image-stacker/id6757908614) | 1.0 (1) | Free | Photo & Video | | [StarEdit](https://appshunter.io/ios/app/staredit/id6723888917) | 4.8 (4) | Free | Photo & Video | | [MacroShader](https://appshunter.io/ios/app/macroshader/id6751045993) | 5.0 (1) | Free | Photo & Video | | [RoboTou Stacker](https://appshunter.io/ios/app/robotou-stacker/id6761755082) | 5.0 (1) | Free | Photo & Video | ## More apps by Ahmed Al-Mahmud - [WidgetGPT: Interface AI](https://appshunter.io/ios/app/widgetgpt-interface-ai/id6755014996) - [AI Shortcuts Builder](https://appshunter.io/ios/app/ai-shortcuts-builder/id6755172604) All apps by Ahmed Al-Mahmud: https://appshunter.io/developer/1844352476 ## Related topics [eagle image stacker](https://appshunter.io/ios/topics/eagle-image-stacker) · [deep sky stacker](https://appshunter.io/ios/topics/deep-sky-stacker) · [image stacker](https://appshunter.io/ios/topics/image-stacker) · [astroshader](https://appshunter.io/ios/topics/astroshader) · [nebulosas](https://appshunter.io/ios/topics/nebulosas) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-11-12.*