September 11, 2024

Unit Converter (v1.7) manual

Hello. I'm android boy, the chief developer of Smart Tools co.,

Google Play store had a lot of Unit Converting apps. But most were inconvenient and difficult to use because of poor and complicated UI (user interface). I've been improving my unit app for 10 years, so that it became intuitive and simple.

This app would not include all units in the world. It shows only common units selected by users' feedback. The different units will appear depending on users' country and language.


※ Introduction video



※ Unit sets
 ① Basic : length (distance), area, weight (mass), volume (capacity)
 ② Living : exchange rate, temperature, time, speed, shoes, clothing, hat, ring
 ③ Science : pressure, force, work (energy), power, torque, flow, current, voltage, density, viscosity, concentration, astronomy
 ④ Misc. : angle, data, fuel efficiency, cooking, illuminance, radiation, prefix, binary (ASCII), time zone, blood sugar, AWG, hardness, number


※ How to use the app
 1) Select a category (Basic / Living / Science / Misc.)
 2) Select a unit set (tab)
 3) Select a unit by LONG-CLICK on the list or click the selector
 4) Click the input box (pencil), enter a number using the keypad


※ Currency (exchange rates)
 - 122 currencies of 140+ countries, Bitcoin and XAU (gold)
 - [My currency] is set automatically by your telecom carrier and language.
 - You can select your region from the list.  All / Majors / Europe / ...

 - The refresh icon gets the latest exchange rates from our servers. (not automatic)
 - The exchange rates are based on Fx-exchangeFxexchangeRate, etc.
 - There may be a delay of 5 to 30 minutes. The rates are for information purposes only.


※ Favorites
You can choose your own 4 favorites in Living, Science and Misc.
Toggle check-boxes in the order you want (①-②-③-④).


※ How to add "Torque" units.


  ① select the Science category
  ② click the favorites icon at the app bar
  ③ release one of 4 favorites

  ④ check the [Torque] set
  ⑤ close
  ⑥ click the [Torque] tab


※ Menu & Settings

 ① Sound effect on/off : it can mute the ads sound (when turned off)
 ② Country selection : different units depending on your country.
 ③ Language selection : 26 languages

 ④ My Currency
 ⑤ Region : [ Europe / North America / Asia / ... ]
 ⑥ Custom list : make your own list

 ⑦ Decimal format : 1,234,567.89 or 1.234.567,89
 ⑧ Vibration : vibration on/off on keypad


※ How to enter fractions
In length and weight set, the keypad has [. /] button that can enter fractions.

ex1) 5 1/4 =>  [5] + [./] + [1] + [./] + [4]
ex2) 3/8 = 0 3/8 => [./] + [3] + [./] + [8]   (Look out!! 3/8 is less than 1.)
       or [3] + [./] [./] + [8]   (new feature)


※ How to enter "ft and inch" at the same time
Select "ft in" unit first. [' "./ ] is the magic button. "lb oz" is in the same way.

ex1) 2' 3.5" =>  [2] + [ ' "./ ] + [3] + [ ' "./ ] + [5]
ex2) 1' 2 5/8" => [1] + [ ' "./ ] + [2] + [ ' "./ ] + [5] + [ ' "./ ] + [8]


※ How to enter "deg min sec"
Select "deg min sec" or "deg" unit in Angle set. You can enter "deg min sec" with [.˚ '] button on the keypad.

ex1) 1˚ 23' 45.67" =>  [1] + [.˚'] + [2][3] + [.˚'] + [4][5] + [.˚'] + [6][7]
ex2) 0˚ 1' 2" =>  [.˚'] + [1] + [.˚'] + [2]


※ How to enter "hh:mm:ss"
Select "hh:mm:ss" or "hour" unit in Time sec. You can enter "hh:mm:ss" with [. :] button on the keypad.

ex1) 1:23:45 =>  [1] + [. :] + [2][3] + [. :] + [4][5]
ex2) 0:00:02 =>  [. :] + [. :] + [2]


※ Data storage / flow ?
This app shows data storage and data flow in data unit set so as to save a tab. It is not a mistake. Similarly, it shows speed and running face units in speed set, too.
By the way, do you know the difference of "kb", "kB", "kib", "kiB", "kbps"?
 b : bit
 B : byte
 k : kilo (1000)
 Ki : kibi (1024)
 M : mega (1000 x 1000)
 Mi : mebi  (1024 x 1024)
 kbps : kilo bit per second

 ex1) 1 kB = 1000 bytes, 1 MB = 1000 kB = 1000 x 1000 bytes
 ex2) 1 KiB = 1024 bytes, 1 MiB = 1024 KiB = 1024 x 1024 bytes


※ When I traveled abroad, I could not find some units.
My app shows different units depending on your country. It can guess your country according to your telecom carrier and system language.

When you travel abroad, other unit sets can appear because of overseas roaming. In this case, select the country in [Country selection] option at the settings.


※ What is the ad-free menu ?
Please watch a reward video for 15-30 seconds, so that all ads will be removed for 9 hours. The information box will appear like paid version. It will be worth it.


※ Landscape mode
It supports landscape mode for tablet PCs. Select more menu (3 dots) at the top-right corner.


※ FAQ
Q. How to copy the result to clipboard?
A. Double-tap on the number. To paste it, long-click on the input box (pencil).

Q. How can I convert from gram to liter?
A. "gram" is weight unit, "liter" is volume unit. They cannot be converted. 1L of water = 1kg, 1L of gasoline = ~0.70kg

Q. "kg" is not a weight unit, but a mass unit.
A. I know. weight = mass x Gravity. "mass" and "weight" are same in Earth.
Above all, "weight" is a friendly word and the public do not understand "mass" perfectly.

Q. I cannot find some essential units.
A. Maybe the list has been scrolled up. Just scroll down the list.

Q. I need more units such as kHz, MHz, GHz ...
A. How about using "prefix" unit set?

Q. How to make video ads mute?
A. Turn off [sound effect] option at the settings.


※ Pro version additional features:
 1) No ads
 2) Info-box for more information (unit name, formula, ...)
 3) More options at the settings (accuracy, layout)
 Get it on Google Play


※ Pending update
- unit arrangement
- custom unit generating
- more style with various colors (Done!)


※ What's new
 - v1.7.1 : Support for Android 14
 - v1.6.1 : Support for Android 11
 - v1.5 : Sound effect on/off, Ad-free menu
 - v1.4.4 : Copy to clipboard (double-tap on the number)
 - v1.4  : Mini calculator (+ - × ÷)
 - v1.3 : Material design, Bitcoin
 - v1.2 : Favorites on Science and Misc.
 - v1.1 : Currency exchange rates
 - v1.0 : Released (Nov, 2013)
https://play.google.com/store/apps/details?id=kr.sira.unit

If you have any idea to improve the app, feel free to contact me at androidboy1@gmail.com. Thank you.

August 27, 2024

Qibla Compass (v1.0) manual

Hello. I'm android boy, the chief developer of Smart Tools co.,

Many "Smart Compass" users have requested the Qibla function. Recently, while updating the direction function in the Pro version, we decided to release a individual Qibla app for Muslims. If you are a "Smart Compass" user, you can use this app very easily.


※ Introduction video


※ What's new
 - v1.0 : Released (Sep, 2024)
https://play.google.com/store/apps/details?id=kr.sira.qibla


The Arabic translation is somewhat poor. If you can help, please email me at androidboy1@gmail.com. Thank you.

December 1, 2023

Smart Calculator (v1.0) manual

Hello. I'm Android Boy, the chief developer of Smart Tools co.,

The pre-loaded calculator app on Galaxy phones was so great that there was no need to develop one separately. But some phones, such as Motorola, do not have a calculator installed, and I found limitations with the Galaxy calculator.

The same design as the existing unit converter was adopted. It makes this app intuitive and simple with a familiar interface. First, I released this app with two types of calculators (Basic, Scientific). Two more tabs are in progress. (money, misc.)


※ Introduction video




※ Calculator Tabs
 ① Basic
 ② Scientific


※ What's new

 - v1.0 : Released (Dec, 2023)
https://play.google.com/store/apps/details?id=kr.sira.calculator

If you have any idea to improve the app, feel free to contact me at androidboy1@gmail.com. Thank you.

September 7, 2023

Privacy Policy (EU)

Privacy Policy for websites


Smart Tools corporation("We", "Our", "Us") has developed this Privacy Policy to help you understand how we collect, use and protect the information. We encourage you to read this Privacy Policy carefully so that you can make informed decisions about your use of our websites("the webs").

By visiting the webs, you agree to this privacy policy and give an explicit and informed consent to the processing. If you do not agree, please leave the webs.

1. Non-personal Data
Non-personal data means information that, by itself, does not personally identify you. We may collect Non-personal data such as your IP address and other properties for purposes of analyzing the webs.

2. Ad serving Technology
We may disclose Non-personal data to third parties and/or allow third parties to collect Non-personal data through their own embedded technology. In order to deliver ads to you, the third-party advertising companies may place or recognize unique cookies, anonymous identifiers or similar technology for non-personally identifiable information. If you would like more information, please follow the link below:
AdSence - http://policies.google.com/privacy

3. Personal Data
Personal data means personally identifiable information that specifically identifies you as an individual (e.g. your name, email address). We collect and store Personal data only with your consent. 

4. Third party terms and conditions
Please note that your access to the webs may be subject to certain third-party terms and conditions and privacy policies. You recognize and agree that we is not liable for any such third-party terms and conditions and any third party’s use of your Personal data. Here are links to the privacy policies of a few of the distributors we use:
Google - http://www.google.com/intl/en/policies/privacy/

5. Disclosure and Transfer of Personal Data
We disclose information to respond to subpoenas, court orders and other legal processes as well as to establish/exercise our legal rights or defend against legal claims. We will share Personal data and Non-personal data in order to investigate, prevent or take action against illegal activities, suspected fraud, potential threats to the physical safety of any person, violations of our Terms of Use or as otherwise required by law.

If you have any questions about this Privacy Policy, please contact us at androidboy@naver.com

Last Update: Sep 07, 2023

June 28, 2023

Privacy Policy (EU)

Privacy Policy for Mobile Applications


Smart Tools corporation("We", "Our", "Us") has developed this Privacy Policy to help you understand how we collect, use and protect the information. We encourage you to read this Privacy Policy carefully so that you can make informed decisions about your use of our mobile applications("the apps").

By installing and using the apps, you agree to this privacy policy and give an explicit and informed consent to the processing. If you do not agree, please do not install and use the apps.

1. Non-personal Data
Non-personal data means information that, by itself, does not personally identify you. We may collect Non-personal data such as your device model number, operating system version, country code and other properties for purposes of analyzing the apps and communicating with you.

2. Ad serving Technology
We may disclose Non-personal data to third parties and/or allow third parties to collect Non-personal data through their own embedded technology. In order to deliver ads to you, the third-party advertising companies may place or recognize unique cookies, anonymous identifiers or similar technology for non-personally identifiable information. If you would like more information, please follow the link below:
AdMob - http://policies.google.com/privacy

* How do I change my GDPR choice? If there is a [Reset settings] menu in the app, use it. If not, select [Clear data] from Storage in App Settings.

3. Location Data
Some of the apps may request your Location data for a functional purpose. We may use various technologies to determine location, such as GPS, WiFi or other network-based data such as IP address. Your GPS geo-location is not accessed without your consent. We do NOT provide your Location data for any advertising networks and third parties except Google.

4. Personal Data
Personal data means personally identifiable information that specifically identifies you as an individual (e.g. your name, email address). We collect and store Personal data only with your consent. We may use your Personal data to send emails to you with informative content about the apps, such as new features and services, special offers, order issues and updated information.

5. Third party terms and conditions
Please note that your access to and use of the apps may be subject to certain third-party terms and conditions and privacy policies. You recognize and agree that we is not liable for any such third-party terms and conditions and any third party’s use of your Personal data. Here are links to the privacy policies of a few of the distributors we use:
Google - http://www.google.com/intl/en/policies/privacy/
Galaxy Apps - https://account.samsung.com/membership/pp
Amazon - http://www.amazon.com/gp/help/customer/display.html?nodeId=468496

6. Disclosure and Transfer of Personal Data
We disclose information to respond to subpoenas, court orders and other legal processes as well as to establish/exercise our legal rights or defend against legal claims. We will share Personal data and Non-personal data in order to investigate, prevent or take action against illegal activities, suspected fraud, potential threats to the physical safety of any person, violations of our Terms of Use or as otherwise required by law.

If you have any questions about this Privacy Policy, please contact us at androidboy@naver.com

Last Update: June 28, 2023

March 29, 2023

Smart Currency (v1.0) manual

Hello. I'm android boy, the chief developer of Smart Tools co.,

As you know, We have a popular unit converter app. The usage rate of currency conversion was high, but it was inconvenient to use due to space limitations.
This app has expanded its functionality after separating the currency section. So it has become more intuitive and simpler with the friendly interface.


※ Introduction video



※ Currency Tabs
 ① Major currencies : USD, EUR, JPY, GBP, CHF, AUD, CAD
 ② All currencies : 120+ currencies
 ③ Favorites : select your own 10 currencies
 ④ Region : long-click to change the selected region. Europe, Asia, ...


※ Chart Tabs
 ①-④ 1 month, 3 months, 1 year, 3 years
 In the list, major currencies and only currencies registered as favorites can be selected.


※ How to use
 1) Select a tab (Major / All / Favorites / Region)
 2) Select an unit by LONG-CLICK on the list or click the selector
 3) Tap the input box (pencil), enter numbers with the keypad


※ Exchange rates
 - 122 currencies of 140+ countries, Bitcoin and XAU (gold)
 - [My currency] is set automatically depending on your telecom carrier and language.

 - When you open the app, the latest exchange rate is automatically loaded.
 - The refresh icon can get the live exchange rates from servers.
 - The exchange rates are based on currencylayeropenexchangeratesexchangerate, etc.
 - A time delay of 5-10 minutes may occur. The rates are for information purposes only.

※ Menu & Settings
 ① Sound effect : it can make the sound of video ads mute

 ② My currency : select your base currency
 ③ Region : Europe / North America / Asia / ...
 ④ Layout : 4 types
 ⑤ Custom list : select your favorites

 ⑥ Decimal format
 ⑦ Vibration : vibration on/off on keypad


※ What's new
 - v1.0 : Released (April, 2023)
https://play.google.com/store/apps/details?id=kr.sira.currency

If you have any idea to improve the app, feel free to contact me at androidboy1@gmail.com. Thank you.

October 25, 2022

Color Picker (v1.0)

Hello. I'm Android Boy, the chief developer of Smart Tools co,.

Recently, some users have requested a color-meter or a color-selector app. Development is not hard, but I kept putting it off because it was a function that wasn't used much.

Sometimes I had to choose the color of a specific screen when drawing an app design.

When drawing app designs, it was sometimes necessary to select the color of a specific screen. I decided to develop a color picker app with a slight modification of the magnifying glass app. :)


※ Introduction video




※ How to get a color
1. Moving - by moving your phone.
2. Touching - by touching the screen.
3. Freezing - after freezing the camera view.
4. Gallery - by loading images stored on your phone.
- Buttons : gallary, auto-focus, flashlight, freezing, ok
  Press the white button. The RGB color code is confirmed at the top. 


※ Menu & Settings
- Sound effect
- Camera zoom


※ FAQ
Q. Why does the app require the storage permission?
A. It is necessary to open gallery and load images.


 What's new
 - v1.0 : released (Nov, 2022)
https://play.google.com/store/apps/details?id=kr.sira.color

If you have any idea to improve the app, feel free to contact me at androidboy1@gmail.com. Thank you.