The Moon is one of the most enigmatic and mystical planets of the Solar system. Change of phases of the Moon exerts impact on events which take place in the world, on behavior of people, their feelings.

A.V.T. Software (Sole Proprietorship Vita Tolstikova) presents MoonCalc Mobile Web App for calculating and displaying Age of the Moon, Phase of the Moon, and Distance from the Moon to the center of Earth. For residents of the Northern Hemisphere, the Southern Hemisphere, and Equator. MoonCalc Mobile Web App uses the W3C Geolocation API (GeoIP).

The technology of responsive design was used when creating the user interface.

The MoonCalc Mobile Web App was designed for educational and cognitive purposes.

In August, 2017 the A.V.T. Software team has made a decision to publish the MoonCalc Mobile Web App on GitHUB (https://github.com/SP-Vita-Tolstikova/mooncalc-mobile) as an open source project.

In honor of the 15th Anniversary of [A.V.T. - Компьютерный учебный центр] (https://avt.dn.ua).

2.1 When the index.html file is opened in the browser, the user needs to allow the Web App to determine the current user location in order to correctly display Age of the Moon, Phase of the Moon, and Distance from the Moon to the center of Earth. For residents of the Northern Hemisphere, the Southern Hemisphere, and Equator.

2.2 In the current release you can calculate the Moon parameters not only for the current time, but for the past and future days. The "Now" button can always go back to the calculation the Moon parameters for the current time. For the four main Phases of the Moon (New Moon, First Quarter, Full Moon, Last Quarter) displays their names.

2.3 The "About" button in the header opens the page with information about MoonCalc Mobile Web App. The "Back" button in the header returns to the previous (Main) page.

2.3.1 The "User Agreement" button on the "About" page opens the page with User Agreement information.

3.1 The MoonCalc Mobile Web App has been successfully tested in the following desktop browsers:

• FireFox v 55.0.2
• Google Chrome v 60.0.3112.113
• Microsoft Edge v 40.15063.0.0
• Microsoft Internet Explorer 11 v 11.540.15063.0

3.2 The MoonCalc Mobile Web App has been successfully tested with the following screen resolutions (from 320x480 to 1680x1050) with different screen orientations (portrait and landscape).

4.1 HTML5

4.2 CSS3

4.3 JavaScript

4.4 [jQuery JavaScript Library v1.8.3] (http://jquery.com/) by John Resig

4.5 [jQuery Mobile Framework v1.2.0] (http://jquerymobile.com/) , Copyright 2012 jQuery Foundation and other contributors

4.6 [DaVinci SDK (SEC Web App SDK 1.0)] (http://davincisdk.blogspot.com/ ), Copyright (c) 2013 Samsung Electronics Co., Ltd.

4.7 [Knockout JavaScript library] (http://knockoutjs.com/) by Steve Sanderson

4.8 [W3C Geolocation API library] (https://www.w3.org/TR/geolocation-API/) by the W3C

The first release of the S40MoonPhase Web App (the predecessor of MoonCalc Web App) was appeared in November, 2011 for Nokia Series 40 mobile devices.

In January, 2012 the [MoonPhase Web App] (https://github.com/SP-Vita-Tolstikova/moonphase) was a participant of the international competition Intel AppUp Developer Challenge: Web Apps Edition, organized by Intel

In the period from 2011 to 2014 were created versions of the MoonCalc Web App for more than 10 different mobile platforms (Nokia S40, Nokia S40FT, Nokia Symbian S60, Nokia Asha Software Platform, Nokia X Software platform, Samsung bada, Samsung Gear, Google Android etc.) that cover dozens of mobile devices