[Android Apps and Games] Skyica:
Searching with the Play Store

Suppose we want to find the best calculator apps that can draw 3D graphs. This will be the main example in this article.

A natural language query

Since Google indicates for its web search that it understands simple questions in natural language (see here), many people might try a query like

However, you will see that

the Play Store search does not seem to understand this.

Without filters, the above query gives about 240 results. Here are the first 50:

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Note that the Play Store slightly varies the results with each query and also “personalizes” them (see here), so you may get somewhat different results.

Of the first 10 results, the last 6 are clearly irrelevant as the apps cannot draw 3d graphs and the descriptions also do not state this (for number 5 to 9, the word 3d or something similar does not even occur, for the last one, the word graph or something similar does not occur).

Of the next 10 results, 8 are clearly irrelevant as you can check.

(The ads are also irrelevant, and I have excluded them from the counting.)

Evaluation of the results

While the number of clearly irrelevant results that are returned is already an indication for the quality of a search engine, the ranking of the actually best and most relevant objects seems to be the most significant measure.

More exactly: The ranking of the objects that would seem the best and most relevant from the information that the search engine possesses, in this case mainly the app descriptions, user ratings, and number of ratings and downloads.

Therefore, I have tried to find all apps with a good user rating (4.5+ stars) or high popularity (100k+ downloads), where the description indicates that they are what we’re looking for in this example (i.e., calculator apps that can draw 3D graphs).

For this, I have examined the results from multiple searches with both the Play Store and App Finder (the ones described in this article and some others), and also used the findings from my comprehensive review of advanced Android calculator apps.

I have found that the following 17 apps (and probably very few others) meet the above criteria:

GeoGebra 3D Calculator / Calculator Suite

Scientific Calculator / Pro (by Philip Stephens)

Graphing Calculator + Math/ Pro,

HiperScientific Calculator / Hiper Calc Pro,

Maple Calculator

TechCalc / TechCalc+,

microMathematics Plus

Visual Math 4D

Mathematics (by daboApps)

Calculator++

Grapher / Pro - Equation Plotter

(Apps that are not compatible with current Android devices are excluded.)

Back to the natural language query

You can check that of the 17 apps from the list above, only 5 occur in the first 50 results.

Scientific Calculator by Philip Stephens is at position ~215, after very many completely irrelevant apps, even though the description indicates that it is a calculator app that can draw 3D graphs and it is quite popular and has a fair rating.

One of the best-rated relevant apps (Scientific Calculator Pro by Philip Stephens) is not returned at all.

You see that

with natural language queries, you may miss most of the best apps.

A simple query

Let us now try a simple query with just the decisive words:

There are about 225 results. Here are the first 50:

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This does not work significantly better:

There are now 4 clearly irrelevant apps in the first 10 results (Graphing calculator plus 84 84, Desmos Graphing calculator, and Graphing calculator (X84) cannot draw 3d graphs, and actually don’t have the word 3d in the description. clkGraphs 3D is not a calculator and doesn’t have the word calculator in the description).

Of the next 10 results, 8 are irrelevant again.

Of the apps from our list, 7 are within the first 50 results. Scientific Calculator by Philip Stephens is at position ~190, results, Scientific Calculator Pro is again not returned .

A look at the sort order

Let us compare 3 apps from the result list: Scientific Calculator, Scientific Calculator Pro, and Graph Plotter, all by Philip Stephens.

The first two have all keywords from the query in the description (and are actually good calculators with good 3D graphing), good to very good user rating, and the first one is also quite popular.

The third one does not have the word calculator in the description (and actually includes only the graphing functionality of Scientific Calculator but not the calculation functionality), has a really bad rating, and is not very popular.

However, the first one is at position ~190, the second one is not returned at all, and the third one in position 33!

Scientific Calculator	Scientific Calculator Pro	Graph Plotter
Description includes all words from the query?	Yes	Yes	No
User Rating	4.2	4.7	2.9
Number of ratings	5600	140	130
Number of downloads	1.3M	1.5k	58k
Position in the result list	~190	not returned	33

It would be acceptable if the Play Store would return some low-rated and less relevant apps early in the result list. The big problem is that

highly relevant apps with good to very good user rating are virtually undiscoverable with a reasonable query.

Using quotes

The obvious problem with the previous two queries was that the Play Store returned mostly apps where decisive words from the query did not occur, for whatever reason.

With Google’s web search, quoting words requires them to actually occur (and in the same exact form), so we can expect that this will help.

(Note that the + operator that seemed to work in Google web search in the past to require words to actually occur does not work in the Play Store)

Let us first try to simply put all words from the last query in quotes:

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The results show that we are on the right track:

There are no irrelevant apps in the first 10 results, and 2 in the next 10.

There are only 37 results total, and 11 of the 17 apps from the list above are included.

The main reason that apps from the list are missing is that quotes request the exact words, while some apps from the list do not contain the exact word graphs.

Before we come to this, note the following:

GeoGebra Calculator Suite is not returned although it does have all exact words in the description.

As noted, there are 2 irrelevant apps in the first 20 results (Weight Loss for Women and Air Navigation Pro). While the first one coincidentally contains the words calculator, 3D, and graphs, the second one does not have calculator in the description. Several other apps further down the list also do not contain all keywords (e.g., 11+ Math), and some do not even contain any keyword (Fox 7 Austin: News)

We see that

Even with quotes, the Play Store search cannot be trusted to return all apps where all keywords occur.

Further, it returns many apps where the keywords do not all occur. Some are completely unrelated to the query.

Using the OR operator

Let us now improve the query to include other word forms and synonyms.

It seems very likely that calculator and 3d occur in these exact forms for all relevant apps (up to capitalization, which is ignored by the Play Store even if quotes are used).

However, we should expect graph or graphing instead of graphs, and synonyms like plot or plots. We can cover these cases with the query

Conveniently but maybe unexpectedly, the OR operator is evaluated before the spaces denoting AND, that is, the above query is evaluated as

“calculator” “3d” (“graph” OR “graphs” OR “graphing” OR “plot” OR “plots”)

(Note that parentheses in queries are ignored by the Play Store search.)

With this query, there are about 110 results total, and 15 of the 17 apps from the above list are included (all within the first 48 results).

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Mathematics by daboApps and Calculator++ are missing, despite having the exact words calculator, 3d and plot in the description. The reason seems to be that Google hides these apps from searches because they don’t comply with some policies, so this is not a problem with the search engine.

Note that there are again very many apps returned where not all required words from the query occur.

Nevertheless, we have seen that

the Play Store search may work far better with quotes than without.

Using filters

Let’s now suppose that we want to find the probably best apps as fast as possible.

The only help that the Play Store offers for this is the 4.0 / 4.5 star filter.

If we apply the 4.5-star filter with the “simple query” above, the results are not better than without the filter:

The total number of results is about the same, and the irrelevant apps with less than 4.5 stars are just replaced by other irrelevant apps with 4.5+ stars.

Of the 10 apps from our list that have 4.5+ stars and are not hidden deliberately (see above), 4 are in the first 20 results, and 5 in the first 50.

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If we apply the 4.5-star filter with the query using quotes and OR, the results are quite good:

There are a total of 30 results, all 10 of the 10 qualifying apps from the list are there, 8 in the first 10 results.

However, there are still many irrelevant apps included, some of which do not contain all required words from the query.

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