Tag Archives: letter quiz

SI Unit Prefixes

The idea of an app about SI Unit Prefixes came to me several months ago. I registered it at the iTunes Connect in September. At last, it’s here for everyone to enjoy.

The English description:

How many meters are in 1 nanometer? How many vertices does Dodecahedron have? Is 1 Mebibyte bigger than 1 Megabyte?
This app will help you to answer these and many other questions about decimal, binary, and number prefixes. It has a complete list of prefixes approved for SI units.

Please check 5 Tables and 5 Quizzes:
* Decimal Multiple: kilo-, Mega-, Giga-, etc.
* Decimal Fractional: milli-, micro-, nano-, etc.
* Number Latin: uni-, bi-, ter-, quart-, quint-, etc.
* Number Greek: mono-, di-, tri-, tetra-, penta-, etc.
* Binary: kibi-, mebi-, gibi-, etc.

A quick reference and an easy way to learn this information essential for everyone studying math, computer science, physics, and chemistry.


1. This app was uploaded several hours after Heterocyclic Compounds, they got into the review simultaneously, and SI Prefixes were approved 7 minutes before Heterocycles.

2. New features:
– This is my first app in the category Reference. Actually, after analyzing how the main page for each category is filled on the App Store, I’m leaning towards publishing all my apps as Games. To get on the first page of Education or Reference Apps, your app has to be picked up by Apple editors. In case of Games, all new free games get into the “New Free” bar.
– Tables show all question / answer pairs. It’s not only convenient for users, but helped me to check all errors and typos quickly during the development.

3. Acknowledgements:
icons for buttons were downloaded from iconmonstr or were created with Font Awesome.



Leave a comment

Filed under Developer Blog, Games

Heterocyclic Compounds

My third chemical app – Heterocyclic Compounds.

The English description:

Heterocycles are parts of:
* Biomolecules (nucleic bases in your DNA and RNA; amino acids Histidine and Tryptophan)
* Important drugs (80% of top-selling drugs contain heterocycles: benzodiazepines, quinine, penicillin, etc.)
* and even Food (sugar has heterocyclic rings too!)

That’s why it’s so useful to know the structures of major heterocyclic compounds for molecular biologists, pharmacists, organic chemists and for general public interested in what the stuff is made from.

This app is the unique place to learn the structures and names of 80+ heterocycles.

* Entertaining letter quiz ‘Structure – Name’
* Nitrogen, oxygen, and sulfur heterocycles
* Everything from Purine to Pyridine


1. This app has a bit aggressive “watermelon” design and its goal is not only to teach millions of iOS users about heterocyclic structures but also test the simplest possible “letter quiz” model. There is one linear mode. No flashcards, no tables. The IAP just removes the ad banner.

The review time now is slightly longer than 1 week.

2. Features:
– One linear mode of 81 heterocycles with random questions after finishing the whole sequence
– English and Russian localizations
– Games – Educational / Word category

3. Acknowledgements:
icons for buttons were downloaded from iconmonstr or were created with Font Awesome.


Leave a comment

Filed under Chemistry

Hydrocarbon Chemical Formula

Word World

My first chemistry app Hydrocarbon Formula has been approved and is on the App Store. I plan this to be a start of a series of apps based on the model “Letter Quiz” where the player sees a picture or a formula and has to build its name from the given letters. There will be both chemical and non-chemical quizzes.

The English description of the game is the following:

This application is essential for students learning the basics of organic chemistry, for teachers, graduate students and professionals checking their knowledge of the subject. There are more than 175 structural formulas: fun to guess – easy to remember. Hydrocarbons are the most fundamental class of organic compounds, so it is very important to know their chemical names.

Questions are logically divided into 6 topics covering all possible hydrocarbons. Begin with crucial structures such as methane CH4, benzene C6H6, and octane C8H18 and then proceed to advance topics learning about benzopyrene C20H12 and cubane C8H8. In each question, guess the name of the hydrocarbon or use the hints.

The compound database is prepared by a PhD chemist. 178 structures and names of:

* Alkanes
* Cycloalkanes
* Alkenes / Alkynes
* Dienes, and Polyenes
* Aromatic Hydrocarbons (Arenes)
* Polyaromatic Hydrocarbons (PAHs)


1. This app was twice rejected because of too-long name (the reviewer asked to move all those “dienes, polyenes” to keywords) and because of failed (?) in-app-purchase. According to the attached screenshot, the IAP did work. So I wrote a letter to the Resolution Center and the app was quickly approved without any additional comments on their side or actions on my side.

2. New features are:
– “Watch Ads” button showing an AdMob interstitial and giving the player 20 hints
– Send an email to the author (asmolgam@gmail.com) button in the app
– 40 hints are given for sharing the info about the app on Twitter or Facebook
– Localization to 5 languages besides English and Russian: German, French, Spanish, Italian, and Portuguese.

3. Acknowledgements: icons for buttons were downloaded from iconmonstr or were created with Font Awesome.


Leave a comment

Filed under Chemistry, Developer Blog