This app calculates only Vaishnava (or Bhagavata) Ekadashi which are Shuddha (or pure): an observance is based on the rule that Dashami or the tenth day during a lunar fortnight should have ended before Arunodaya (96 minutes period before sunrise on the Ekadashi or the 11th day in a lunar fortnight).
Note that Smartha Ekadashis are not supported (available in any Hindu calendar).
Full support for ISKCON: this Vaishnava calendar implements both standards of ISKCON: before 1990 and after 1990. The first standard was established by AC Bhaktivedanta Swami Prabhupada and was widely used in ISKCON from the beginning to year 1990 AC. This standard uses Shri Mayapur as the location for calculating the day, when Vaishnava events are celebrated all around the world. In 1990 AC the second standard was proposed: instead of using Shri Mayapur it was advised to use current location.
★ It doesn't have unwanted Popups, Spam, Ads and Notifications.
★ Application size is small and it consumes very small memory space.
★ It is offline application - it does not require Internet connection.
★ It doesn't retrieve or store any identifying information.
★ It doesn't collect anonymous usage data.
★ It has very simple interface.
1) configurable program notifications in the system status bar
2) main screen with:
-- the date of the next Shuddha Ekadashi fasting
-- the period of breaking the fasting
-- description of Ekadasi
3) Daylight Saving Time (Summer Time) support for Europe, USA and Australia
4) built-in database of 4,000 cities to select 'Current location'
5) full support for ISKCON:
Both algorithms of calculating the start of the fasting have been implemented:
-- a) using Shri Mayapur (near Navadvipa, West Bengal, India)
-- b) using the 'Current location'
Notes for ISKCON:
-- a) used by AC Bhaktivedanta Swami Prabhupada. This algorithm was widely used until 1990
-- b) alternative algorithm proposed in 1990
6) support Hindi, English, Ukrainian, Russian, Hungarian and Portuguese.
7) "Set Date" and "Set Time" are a part of time machine which can be used to travel to an arbitrary point in time (currently years 1961-2061 are supported) and get information about Ekadashi fasting for that moment. "Refresh" is used to return to current moment.
Note: the application doesn't save a time or info between sessions. Every time the app is launched it takes current time from system clock and makes calculations again.
8) Dates calculated with "Use 'Current location'" option (i.e. using alternative algorithm) correspond with current ISKCON calendar - "Gcal 2011" (Gaurabda Calendar written by Gopalapriya pr. from ISKCON Bratislava).