III vs Periodic Table of Elements+
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
III
Calculate material properties for III-V compound semiconductors like AlGaInAsP. It determines compositions, lattice constant, strain, bandgap, and effective masses for InP or GaAs substrates.
- III-V compound semiconductor calculations
- Material property determination
- Composition calculation (x, y, z)
- Lattice constant and strain analysis
- Bandgap and effective mass calculation
- Supports InP and GaAs substrates
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Application to calculate the compositions and material properties of a III-V compound semiconductor. Either InP or GaAs is assumed for the substrate. Some of the compositions and material parameters of the AlGaInAsP compound semiconductor are specified to determine the remain unknown parameters. The following properties are shown as a result: compositions (x, y, z), lattice constant, strain, bandgap, relative energy positions of the conduction and valence bands, and effective masses of the electron and holes.
Periodic Table of Elements+
This educational app provides a compact Mendeleev's table with extensive chemical element data. It allows users to create molecular formulas, calculate their mass, and access detailed Wikipedia information for each element. Designed for students and chemistry enthusiasts, it offers VoiceOver accessibility and efficient space utilization.
- Mendeleev's table reference
- Molecular formula composer
- Molecular mass computation
- VoiceOver accessibility
- Links to Wikipedia pages
- Copyable element information
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A quick Mendeleïev's table using a little space. Accessible with VoiceOver, it is a useful reference for students and people interested in chemistry. It reports many data related to chemical elements, that you can select and copy. With this app you can create the molecular formula by long pressing the symbols and compute its mass. The app also includes links to the Wikipedia pages of the elements, for extensive information. - Composer for molecular formulas - Computes the molecular mass - Accessible with VoiceOver - Optimized to use a small space - Includes many elements’properties - Allows to copy the element’s information - Link to wikipedia pages for more information
Screenshots
Verdict
The clearest difference is price: Periodic Table of Elements+ at Free against III's $2.99. Periodic Table of Elements+ also leads on rating (4.7 vs 4.0) and ratings volume (60 vs 1). III's advantage is ads (none vs shown) and review sentiment (100% vs 67%). On in-app purchases 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
Periodic Table of Elements+ is free to download; III costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Periodic Table of Elements+ holds the better App Store score, 4.7 against 4.0. That said, the two scores are not equally well evidenced: Periodic Table of Elements+ has 60 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 100% of III's written reviews are positive against 67% of Periodic Table of Elements+'s, so the app with the better star average is not the one people write more warmly about.
III ships an update every 17 months, Periodic Table of Elements+ every 7 months. Both last shipped on October 30, 2026.
| Parameter | III | Periodic Table of Elements+ |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 4.0 (1 ratings) | 4.7 (60 ratings) — better |
| Positive reviews | 100.0% of reviews — better | 66.7% of reviews |
| Number of ratings | 1 | 60 — better |
| Update frequency | Every 17 months | Every 7 months — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Paid | Ad-supported — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 11.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 10 MB | 38 MB |
| Age rating | 4+ | 4+ |
| Developer | Takuya Ishikawa | Sonya Marcarelli |
Customer experience
III
Periodic Table of Elements+
In-app purchases
III
No in-app purchases
Periodic Table of Elements+
No in-app purchases
