Comparison

DifCal vs (Open Source) Periodic Table

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

Head to head
About

DifCal

Features
Read full description

Calculate diffraction angles for a particular crystal with a defined orientation matrix. New crystals can be added to the database. Energy/wavelength can be changed. Currently knows about 4-circle, Z-Axis and Theta-Theta diffractometers as well as 2-circle, powder and amorphous diffraction modes. Current crystals include silicon, diamond, GaAs, Muscovite (mica), graphite, many 3-5 and 2-6 crystals. There are separate screens for setting the crystal (or creating a new one), defining the orientation matrix, defining the diffractometer mode, and calculating either angles, given h,k,l, or hkl given a set of angles. With the larger screen of the iPad all the controls are visible on a single page.

About

(Open Source) Periodic Table

Features
Read full description

A clean, free periodic table for chemistry students, teachers, and curious people. Explore all 118 elements in an interactive table, then tap into detailed element cards with atomic, physical, discovery, and isotope data. Switch color modes to see trends across the table, search by name or symbol, compare properties, and use practical tools when homework or curiosity sends you down a chemistry rabbit hole. FEATURES Interactive Periodic Table Pinch, pan, zoom, and tap through the full periodic table with category colors and property heatmaps. Element Quiz Learn symbols, names, atomic numbers, and element families with quick 10-question rounds. Start with the first 20 elements and work up to all 118. Element Details See atomic mass, density, melting point, boiling point, electronegativity, radius, electron shells, discovery facts, isotopes, and more. Safety Data GHS hazard pictograms, signal words, and hazard statements for 77 elements, free. No PRO lock. Search and Lists Find elements quickly by name, symbol, or atomic number. Isotopes Browser Browse thousands of nuclides with half-life, decay, abundance, and nuclear data. Molar Mass Calculator Parse formulas with nested groups and hydrates, then see the element-by-element mass breakdown. Chemistry Tools Balance equations, review common reactions, inspect trends, and use reference tables for ions, solubility, constants, and organic series. Mini Academy and Dictionary Learn core chemistry ideas with compact lessons, glossary entries, and quick checks. No ads. No paywalls. No account required. 100% Open Source The complete source code is public - see it, audit it, or contribute at https://github.com/Open-Apps-Studio/periodic-table

Screenshots

DifCal4 screens
(Open Source) Periodic Table4 screens

Verdict

The call

The clearest difference is update cadence: (Open Source) Periodic Table at fortnightly against DifCal's every 15 months. DifCal's advantage is device support (3 vs 1) and iOS requirement (12.0 vs 16.4). On price, ads and in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

DifCal ships an update every 15 months, (Open Source) Periodic Table fortnightly. The most recent releases landed on October 10, 2026 and October 5, 2026 respectively.

Scorecard3 real differences · 3 level
DifCal versus (Open Source) Periodic Table: the parameters behind the verdict, then further details
ParameterDifCal(Open Source) Periodic Table
PriceFreeFree
Update frequencyEvery 15 monthsFortnightly — better
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS12.0 — better16.4
Further details — not scored
Size9 MB47 MB
Age rating4+4+
DeveloperSean BrennanAHMET EMRE DEDELER

In-app purchases

None

DifCal

No in-app purchases

None

(Open Source) Periodic Table

No in-app purchases

Questions

Is DifCal free?
DifCal is free to download, with no in-app purchases.
Is (Open Source) Periodic Table free?
(Open Source) Periodic Table is free to download, with no in-app purchases.
Do DifCal or (Open Source) Periodic Table have ads?
Neither DifCal nor (Open Source) Periodic Table shows ads.
Which is updated more often, DifCal or (Open Source) Periodic Table?
DifCal ships an update every 15 months, and (Open Source) Periodic Table fortnightly. Most recently, DifCal was updated on October 10, 2026 and (Open Source) Periodic Table on October 5, 2026.

Other comparisons