Star Stacker vs Mosaic
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Star Stacker
Create stunning star trail images and time-lapse videos from sequences of night sky photos. Offers various effects like full trails, faded trails, shooting stars, and warp mode. Supports importing photos from your device's gallery.
- Create star trail images
- Generate time-lapse videos
- Full trails effect
- Faded trails effect
- Shooting star effect
- Warp mode effect
- Import photos from gallery
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Star Stacker allows you to import a sequence of star photos taken throughout the night and turn them into star trail images or a time lapse video. After importing you can create the images and/or a time-lapse video with a few different effects. - Full trails - every star at full brightness - Faded trails - Stars get brighter as the process runs - Shooting star - Like faded trails but the last image is brighter than any previous giving a shooting star effect - Javelin - Both ends of the trail are faded - Warp mode - zooms into the image stack slowly creating a warped effect. This will also affect the foreground so post processing may be required if the images have the foreground included. You can also choose to save a video of the time-lapse based on the options used for the image stacking. Can import images from your photos app. RAW files that have been recently imported from an SD card reader, may take a few minutes before the full resolution files are available. There are resolution limits depending on the device being used and the memory it has: - 6gb - 62mp - 5gb - 62mp - 4gb - 62mp - 3gb - 42mp - 2gb - 30mp
Mosaic
Easily create professional-quality photos with stunning background blur effects. This app uses AI to automatically detect and blur backgrounds, offering various blur styles like motion, zoom, and soft focus. Achieve artistic looks or clean product shots with high-resolution, watermark-free exports.
- AI background blur
- Automatic background detection
- Realistic depth and focus
- Customizable blur styles (motion, zoom, linear, soft)
- High-resolution export
- No watermarks
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Blur backgrounds, hide faces, and make every photo pop — in one tap. Blurr uses AI to find the person in your photo, so you can blur the background for a pro portrait look or hide faces, text and private details before you share. SEE IT ON YOUR PHOTO FIRST Pick a photo and every style is instantly previewed on your own picture. Tap the one you like and fine-tune it. BLUR BACKGROUNDS LIKE A PRO • AI subject detection — no manual masking • Portrait bokeh, soft focus, motion, and zoom blur • Cinematic, Dreamy, Noir, Tilt-Shift, Spotlight and more looks • Adjust strength and style with simple sliders HIDE WHAT SHOULDN'T BE SEEN • Blur or pixelate faces automatically • Blur or pixelate text: license plates, addresses, names, screens • Brush to blur exactly the areas you choose, with undo REMOVE BACKGROUNDS Cut out the subject and save a transparent PNG, ready for stickers, product shots, and designs. Or swap the background for a clean studio white or a bold gradient. CREATIVE EFFECTS Neon Glow, Duotone, Halftone, Pixelate, Crystallize, Twirl, Vortex, Glass, Water, Hologram and dozens more. MADE FOR SHARING • Crop to Instagram, Stories, TikTok and other popular sizes • Save to Photos or share anywhere • Import from your library or Files Perfect for portraits, selfies, product photos, travel shots, and privacy-safe sharing. PREMIUM Go Premium to unlock all Pro templates, full-resolution exports, and an ad-free experience. Free users can save in standard quality. • Payment is charged to your Apple ID account at confirmation of purchase. • Subscriptions renew automatically unless auto-renew is turned off at least 24 hours before the end of the current period. • Your account is charged for renewal within 24 hours before the end of the current period. • If you start a free trial, any unused portion is forfeited when you purchase a subscription. • Manage subscriptions and turn off auto-renewal anytime in your Account Settings. Privacy Policy: https://mobile-apps.dev/blur-photo-privacy-policy/ Terms of Use: https://mobile-apps.dev/blur-photo-terms-of-use/
Screenshots
Verdict
The clearest difference is price: Mosaic at Free against Star Stacker's $3.99. Mosaic also leads on update cadence (every 9 days vs every 2 months) and rating (4.6 vs 4.3). Star Stacker's advantage is in-app purchases (none vs 7) and chart position (#157 vs unranked). On review sentiment, ratings volume, 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
Mosaic is free to download; Star Stacker costs $3.99 up front. Mosaic sells 7 in-app purchases, starting at $1.99 per 7 days. Star Stacker asks for nothing beyond the download.
Mosaic holds the better App Store score, 4.6 against 4.3. Both are backed by a comparable volume of ratings — 99 and 128 respectively. Written reviews split almost evenly too, at 57% and 57% positive.
Star Stacker ships an update every 2 months, Mosaic every 9 days. Both last shipped on November 3, 2026.
| Parameter | Star Stacker | Mosaic |
|---|---|---|
| Price | $3.99 | Free — better |
| Rating | 4.3 (99 ratings) | 4.6 (128 ratings) — better |
| Positive reviews | 56.9% of reviews | 57.1% of reviews — better |
| Number of ratings | 99 | 128 — better |
| Update frequency | Every 2 months | Every 9 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Best chart rank | #157 — better | — |
| Devices | iPhone, iPad, Mac — better | iPhone, iPod |
| Requires iOS | 17.0 | 15.6 — better |
| Further details — not scored | ||
| Size | 4 MB | 244 MB |
| Age rating | 4+ | 4+ |
| Developer | michael webb | Viacheslav Khakhulin |
Customer experience
Star Stacker
Mosaic
Bugs and requests
Star Stacker
Reported bugs
12 issues- App crashes when starting stack
- App crashes when attempting to stack
- App crashes during stacking process
- App crashes when rendering video
- Cannot load photos
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- Cannot enter the app
- Cannot select photos after choosing specific access
- App crashes at nearly 90%
- App crashes after stacking completes
- App crashes on MacBook Pro
- App crashes when trying to stack images
- App crashes when adding images
Requested features
12 requests- Option to export live photos
- Help info for stacking options
- Manual stacking option
- Advanced editing software
- Automatic alignment function
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- Ability to set picture format
- Support for .raw files
- Ability to import from Files app
- Option to select all photos
- Clear all option
- 4K video export
- Chinese language support
Mosaic
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Star Stacker
No in-app purchases
Mosaic
- Weekly Premium$1.997 Days
- Monthly3 Days trial$2.991 Month
- Monthly Premium$2.991 Month
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- Quarterly3 Days trial$5.993 Months
- Yearly3 Days trial$11.991 Year
- Yearly Premium$11.991 Year
- Premium$17.99









