Stars Blinker vs Decay Lab
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Stars Blinker
This app helps deep-sky photographers compare two images of the same celestial area taken at different times. It highlights changes in object position or brightness by blinking them, making it easier to spot phenomena like variable stars or asteroids.
- Compare two deep-sky images
- Highlight changes in object position/brightness
- Align images using three stars
- Use images from different instruments
- Adjust blinking interval
- Save animations as movies
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Stars Blinker is aimed to anyone takes Deep-Sky pictures. The app allows to compare two images of the same area taken at different times, with the same or different instruments. Changes, are highlighted by the blinking of any object (star, asteroid, etc.) that only appears in one of the images or has changed position or brightness between a shot and the next. After shooting pictures of stars clusters, nebulae, galaxies and so on, often you would check if there are changes compared to the “normal" appearance of the photographed area. To do it, usually you have to search for a picture (or map) of the same area and check brightness and location of each object. Unless you have a blink comparator that, alternating the vision of two shots obtained at different times, allows to detect and highlight changes or transient phenomena (comets, variable stars, novae and supernovae, asteroids etc.). In the comparator, the sample image and the reference are shown alternately after being aligned with each other. If an object is present in only one of the pictures, it blinks and can be easily found and marked. Instead, if an object has changed position between two shots, during the animation it bounces back and forth, showing the path traveled. With Stars Blinker you can: - load pictures from the local Photo Gallery or from your iCloud; - easily align the two images: just mark the same three stars on each picture and press a button: the sample image is rotated, resized and moved to overlap the reference picture; - use images made with different instruments (I.e. comparing your picture with snapshots taken from online maps and catalogues); - manually refine alignment; - adjust blinking time interval; - invert colors to compare picture in negative; - zoom and pan the animation to frame a specific area or to examine in detail the images; - subtract Reference image from Sample to emphasize any changes; - insert a mark to highlight the position of a Transient; - add labels to report subject, date and time of shooting etc.; - save animations as short movies in your local Photo Gallery.
Decay Lab
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DecayLab makes radionuclide decay calculations and radiation unit conversions quick and straightforward. Designed for nuclear medicine professionals, researchers, educators, and students, it provides a clean, focused workflow that works entirely offline. Key features: • Calculate radioactive decay for a wide range of radionuclides • View activity at different reference and calculation times • Apply decay corrections quickly and consistently • Work with Bq, kBq, MBq, GBq and TBq, alongside nCi, µCi, mCi and Ci • Convert absorbed dose in Gy and rad, and equivalent dose in Sv and rem • Convert dose rates per second, minute, hour or day • See one value in every other unit at once, rather than one pair at a time • Access built-in radionuclide half-life data for 1,625 nuclides • Use all calculation features without an internet connection Gray and sievert are kept in separate tables. Converting between them requires a radiation weighting factor, which is a judgement about radiation type rather than a unit conversion, so DecayLab does not offer it. DecayLab is useful for: • Nuclear medicine technologists • Medical physicists • Radiation safety professionals • Researchers and educators • Students in nuclear medicine and related fields Whether you're checking an activity value, preparing calculations for a workflow, or studying radioactive decay, DecayLab keeps the process clear and efficient. Important: DecayLab is a calculation and educational tool. Results should be independently verified before being used in clinical, diagnostic, therapeutic, or safety-critical decisions.
Screenshots
Verdict
The clearest difference is rating: Decay Lab at 5.0 against Stars Blinker's 4.0. Decay Lab also leads on in-app purchases (none vs 1). Stars Blinker's advantage is iOS requirement (12.0 vs 17.0). On price, 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
Both are free to download. Stars Blinker sells 1 one-off in-app purchase. Decay Lab asks for nothing beyond the download.
Decay Lab holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
| Parameter | Stars Blinker | Decay Lab |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (1 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 | 1 |
| Update frequency | — | Every 4 days |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free | — |
| Devices | iPad | iPhone, iPad — better |
| Requires iOS | 12.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 25 MB | 6 MB |
| Age rating | 4+ | 4+ |
| Developer | Roberto De Lorenzo | Carlos Uribe |
In-app purchases
Stars Blinker
- Unlock all features$1.99
Decay Lab
No in-app purchases









