Comparison

Periodic vs CosmicTelescope

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

Head to head
About

Periodic

Features
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The PeriodicTableElements is an elegant app that is interactive and fun. Easy to use, easy to understand, simple and effective. It shows the periodic table of elements in variety of ways 1) Classic grid with name that is color coded. You can configure it to look however you like. 2) Visually appealing electron distribution. 3) Visually appealing Lewis dot structure. 4) List that can be sorted based on different element properties like group, period, category etc. These awesome periodic tables can be shared by simple double click anywhere on the table. It is possible to copy the periodic table diagrams as high quality SVG xml. Drag your finger on the periodic table canvas to update elements automatically or tap on an element to see more details. Tap on an element and all the rest of the related elements are highlighted. Details of a selected element is shown in a beautifully drawn animated element. Tap on the animated element and you will see more details that can also be shared. Tapping on the list element will navigate you to a page that shows details of the element. It automatically saves your hard work locally on your device so you can come back and pick up from where you left off as your great effort will not be lost. This is a perfect app if you are a student learning chemistry. This is an app for all student groups. From high school to college to university students. Be creative. Enjoy the app!

About

CosmicTelescope

Features
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CosmicTelescope is an app developed by an astrophysicist for astrophysicists. It consists of a toolkit of astrophysics calculators designed to provide immediate access to commonly used tools for astronomy and cosmology to astronomers and researchers (but also students and amateur astronomers). This app was developed by thinking about the instruments I found myself wishing existed, many times during my own work โ€” "if only an app with this tool existed..." Everything runs on your device โ€” no account, no internet connection, no ads, no tracking. The app is shared for free, for purely scientific purposes, with the sole hope of giving useful support to friends and colleagues in their work. This is a first version of an app that is intended to constantly expand its functionalities. Please note that the app may contain errors, so I strongly recommend always cross-checking the results, and please send me any bugs you find at pbergapps@gmail.com. FEATURES Cosmology Enter a redshift and a customizable cosmological model, and compute the commonly used cosmological quantities (e.g. age of the universe, Hubble parameter, and comoving/angular-diameter/luminosity distances). Gravitational Lensing Define a lensing system and compute the physical properties characterizing it (e.g. angular diameter distances, lensing critical surface density, masses). An interactive tool also lets you see the critical curves, caustics, image positions, magnifications, and time delays. High-z Sources Support for the study of high-z sources: convert between angular size, physical size, and โ€” optionally taking the lensing effect into account โ€” magnification for high-redshift sources, with observed-wavelength and cosmic-time context. Observations / Survey Planning Characterize telescope pointings and observation FOVs for a custom or preset telescope/instrument, including new instruments and facilities still under construction. Telescopes Pick a real telescope, then an instrument, then check one or more of its filters or spectrograph coverage, and see them plotted on the observed wavelength axis โ€” photometric filters with their real transmission curves, spectrographs as their real wavelength coverage โ€” together with each band's range, PSF or resolving power, and (at a chosen redshift) rest-frame coverage. Visibility Planner Helps astronomers prepare their next observation: pick an observatory and target, and see altitude tracks against twilight and Moon conditions, airmass, best observing time, and a "find the best night in the next 365 days" search โ€” with a world map and shareable plot. Data Archive Browse a comprehensive list of astronomical data archives (including surveys like Euclid) and open them directly in your browser. Spectral Lines Map known emission/absorption lines into an observed wavelength window for a given redshift, with SED template overlays and the same telescope/filter/spectrograph overlays as the Telescopes tab. Pinch to zoom or drag with one finger to pan the plot. Unit Converter Convert between the units used throughout astrophysics: wavelength, flux, magnitude systems, angles, and more. Exposure Time Calculator Helps astronomers prepare their next observing proposal: pick a real telescope, then instrument, then filter (imaging or spectroscopy mode is set automatically), and compute signal-to-noise, limiting magnitude, or required exposure time, with sky-background and cross-band reference-magnitude support. Physical Constants A reference table of physical constants commonly used in astrophysics and cosmology, with unit toggles. Every tab includes a short guided tour (with a restart option in the app menu) so new features are easy to discover. Credits: the development of this app was supported by the power of the most advanced AI tools, including Gemini, Claude Code, and Codex.

Screenshots

Periodic4 screens
CosmicTelescope4 screens

Verdict

The call

The clearest difference is price: CosmicTelescope at Free against Periodic's $1.99. On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

CosmicTelescope is free to download; Periodic costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Scorecard1 real difference ยท 5 level
Periodic versus CosmicTelescope: the parameters behind the verdict, then further details
ParameterPeriodicCosmicTelescope
Price$1.99Free โ€” better
Update frequencyEvery 5 weeksโ€”
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.115.1
Further details โ€” not scored
Size31 MB28 MB
Age rating4+4+
DeveloperOm Prakash ChapagainPIETRO BERGAMINI

In-app purchases

None

Periodic

No in-app purchases

None

CosmicTelescope

No in-app purchases

Questions

Is Periodic free?
Periodic costs $1.99, with no in-app purchases.
Is CosmicTelescope free?
CosmicTelescope is free to download, with no in-app purchases.
Do Periodic or CosmicTelescope have ads?
Neither Periodic nor CosmicTelescope shows ads.

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