Category Archives: Developer Blog

New app: Flags Quiz – World Continents

After a long pause, we are excited to present a new app called Flags Quiz – World Continents.

“Download
Get it on Google Play

This app continues our geography quiz series.

The English description of the game is the following:

This is the best opportunity to learn all important flags of the countries and territories of the Earth.
They are divided into 6 groups:
1) Europe (62 flags)
2) Asia (53 flags)
3) North and Central America (38 flags)
4) South America (13 flags)
5) Africa (56 flags)
6) Australia and Oceania (24 flags)

Each continent provides several distinct learning modes:
1) Spelling quiz (easy and hard)
2) Multiple-choice quiz
3) Time Game (give as many answers as you can in 1 minute)
4) Flashcards

This app is translated into 16 languages.

Learn all flags from Afghanistan and British Virgin Islands to Wales and Zimbabwe!

*****
As you can see, the gameplay was substantially improved comparing to our previous apps. Now you can earn stars for completing each quiz mode for every continent. Australia and Oceania is especially challenging. Flashcards provide a learning and training opportunity.

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

Thanks!

1 Comment

Filed under Developer Blog

Cities of the World

My first app of 2015—Cities of the World—continues my successful series of Geography Apps and is translated into 15 languages. It has been released for both platforms:

“Download
Get it on Google Play

The English description of the game is the following:

Guess and spell the names of the 100 most famous cities of the world using the pictures of their landmarks (New York, London, Beijing and so on).
– You won’t get stuck if you don’t know the answer because the app allows you to guess each word letter by letter and will immediate show if the next letter is incorrect!
– The cities are arranged in the order of increasing difficulty and are divided into two levels. If you think that the first questions are too easy, just proceed forward until you encounter really hard ones.
– Two quiz modes: 1) for those who like spell city names and 2) for those who prefer to choose from 4 answers.
– Very entertaining learning experience for all geography and traveling fans!

This app is translated into 15 languages: English, German, French, Spanish, Portuguese, Italian, Russian, Swedish, Dutch, Danish, Norwegian, Japanese, Chinese, Korean, and Turkish languages.

*****

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

Thanks!

Leave a comment

Filed under Developer Blog

My Best Apps of 2014

In the end of the year, I would like to share some of my data and assign “Best Apps” in Geography and Chemistry categories.

I will remember 2014 as the Year of Quizzes. Since Hydrocarbons appeared on iOS on January 31, I have released more than 40 distinct quizzes. In September, most of them were published on the Google Play Store as well. And these quizzes were much more successful than my first apps released last year. So far I have 578k downloads for iOS and 215k downloads for Android. Total earnings are well higher $20k.

Geography

The most profitable iOS app: 50 US States – $4k

“Download
Get it on Google Play

The most downloaded iOS app: European Countries – 55k

“Download
Get it on Google Play

The most profitable Google Play app: Swiss Cantons – $650

“Download
Get it on Google Play

The most downloaded Google Play app: Capitals of the World – 38k

“Download
Get it on Google Play

Chemistry

The most profitable and most downloaded iOS app: Inorganic Acids – $800 and 31k downloads

“Download
Get it on Google Play

The most profitable Google Play app: Chemical Substances – $66

“Download
Get it on Google Play

The most downloaded Google Play app: Functional Groups – 14k

“Download
Get it on Google Play

So it’s clear that Geography is more popular than Chemistry and it’s likely that I’ll continue moving in this direction. A funny fact for me is that the most promising app of recent months Flags of the World hasn’t won in any of 4 categories. Let’s see how it will change in 2015!

“Download
Get it on Google Play

2 Comments

Filed under Developer Blog

Ads Stats

I haven’t started experimenting with different ad networks yet and use standard solutions in my apps: AdMob (banners and interstitials for iOS and banners for Android) + iAd (only banners for iOS). Since Android versions of apps appeared very recently, I have a reliable stats only for iOS.

Ads are mediated through AdMob with the “Optimize AdMob Network” option checked. It results in a much higher number of impressions and higher eCPM for AdMob than for iAd, but I found that this scheme generates the greatest income. It’s important to remember that AdMob works everywhere, while iAd is available only in 16 countries.

Below, I show the Ads Stats for a typical week in August-September. There are always daily fluctuations in income with Saturday usually being the best day.

The numbers are self-explanatory for those in mob dev business. My 46 apps bring about $150 and 140k impressions a day. Fill rates are very high and the cost per click is about 15 cents. Of course, these number may vary between apps and countries. Here is the stats for the most profitable app Flags of the World (AdMob banner, AdMob interstitials, iAd banner):

Banners are shown constantly interchanging AdMob/iAd while interstitials are shown after every 15 questions. I’d like to point out that there is an in-app-purchase to remove ads for $0.99 and thus all these stats may be slightly disturbed comparing to actual app usage.

Leave a comment

Filed under Developer Blog

Financial Report – September 2014

All important apps have been rewritten for Android and now I have 46 apps on the Apple App Store (iOS) and 38 apps on the Google Play Store (Android).

Here is my income from Jan 2014 (about $15.5k so far):

In January, I was earning on average $3.5 a day. Since August 20, my daily income haven’t fell below $150 / day. Total income in August is $4,198. This amount is comparable with my salary that I had 2 years ago as a chemistry postdoc at Berkeley.

75% of money are from showing ads and only 25% from sales and in-app-purchases (next week, all my apps can be downloaded for free).

The most profitable are Geography apps, such as:

50 US States (iOS, Android) $2,532 (16.5% of total income).
European Countries (iOS, Android) $2,098 (13.6%).
Flags of the World (iOS, Android) $1,448 (9.5%).

Localization into 9 languages was a very clever decision. United States accounts for 28.4% of total income, Germany 10.9%, Russia 8.8%, France 6.7%, and so on.

The Google Play store is very different from the Apple App store in download trends, search optimization and algorithms. By now, the income from Android apps is just $15.29 but it is constantly growing and I’m just in the beginning of understanding this platform.

Many thanks to everyone who supports me. I will be glad to answer your questions and hear your suggestions how to improve my apps.

7 Comments

Filed under Android, Developer Blog, Finance, Geography

Geography Games

Today I updated this site by renaming the undeveloped Tutorial page to Geography and moving there 11 geography-related apps I have created so far. Thus, all apps are divided to three categories: Geography, Chemistry, and Games. The later can be more precisely called “Miscellaneous Apps” because it includes everything non-chemical and non-geographical: quizzes, puzzle games and even my only app in the Entertainment category.

Meanwhile, I have 4 apps waiting for review and I am going to make several changes on the site in the nearest future. It’s unsurprising that many things changed since the time when I started it a year ago with only one published app.

Leave a comment

Filed under Developer Blog

German States

I continue my series about the regional geography. Today let’s welcome German States. In terms of revenue from my apps, Germany is the third country after the United States and Russia. And everyone has heard about Bavaria and Bremen.

The English description of the game is the following:

Learn all 16 States of Germany: Bavaria, Brandenburg, Berlin and all others.
* names
* maps
* capitals
* flags
* coats of arms

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

Thanks!

Leave a comment

Filed under Developer Blog, Games

Hydrocarbons 1.1

The new version of the Hydrocarbons app has been approved after 6 days of waiting and just 1 min of reviewing.

The major reason of the update was to add “promo nodes” (links after questions) to my recent apps. I moved the “Watch Ads” button from the Settings to the game as well, though it seems that the whole idea with interstitial screen ads doesn’t pay off in my case. There are several minor fixes in chemical formulas in their style or sizes. In the main menu, I highlighted that two locked modes (“Dienes & Polyenes” and “Polycyclic Aromatic Hydrocarbons”) can be unlocked (= bought) in Settings. The word “Buy” near an inactive button was a bit confusing. The letter keys were made bigger in case of iPhone/iPod. The sounds of correct letters now grow in their pitch which is not as monotonous as it was in 1.0.

Leave a comment

Filed under Chemistry, Developer Blog

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.

Thanks!

Leave a comment

Filed under Developer Blog, Games

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.

Thanks!

Leave a comment

Filed under Chemistry, Developer Blog