Yesterday I released GPS Prasna my first application using the Google Android phone SDK.  If you happen to have an Android phone your can find it at the Android Market.  The program is free and is a very basic program which takes advantage of the location services to find your current coordinates to generate a prasna chart.   You can select either Northern or Southern style chart layouts.   The phone gets the time and time zone from the phone itself.  Currently in the US the only provider of an Android phone is T-Mobile which offers the G1.  However other Android phones have been announced by Samsung and Sony/Ericsson which probably means other wireless providers will be offering Android phones.  Here's a link for more information on Android:

The advantage of using the Android system over others is that the location and map services from Google can be used for free by the developer (the user will have turn on the services and make sure their plan includes data access).  Another development systems may charge a healthy fee to implement their location services.   So the path of least resistance was the Android phone.  Also I noted comparing the G1 phone to a Samsung Instinct and the Apple iPhone that the G1 had the largest display though not by much.  In general these data enabled phones have smaller displays than PDAs.  So if you are considering getting such a phone be sure to visit stores selling them to see if you like the display size.  On the Pocket PC version of Jyotish Tools I had to provide a larger display  of the horoscope feature and Pocket PCs have a much larger screen!  And also most of these phone require extra data service fees so take that into account especially if your present wireless program does not provide Internet access.

The new free program was derived from a version of Jyotish Tools for the Android which I have been working on.  Getting the actually horoscope parts of the program was easy but though there is a keyboard on the G1 which is mainly only usable in "landscape mode" required some testing and development of special input functions for time zone, longitude and latitude.  These will duplicate the Android date and time input designs which are large enough to be read easily and adjusted even by large fingers.  On PDAs these could be smaller because they used styluses.

Also my plan for Jyotish Tools is to allow you to click on an button which will take you to Google Maps and find the location you want that way as an option.  However Google maps is only good for longitude and latitude but not time zone of the location so a built-in altas may still be useful.  Even if the time zone were available it would not be historic so the zone may have changed over the years.  And time zones especially ones that use Daylight Saving Time make the astrologer's work more difficult.  I understand that President Obama would like to do away with DST.  Turns out that it doesn't actually save energy and has some hidden costs from accidents especially as people try to adjust in the spring.

As for other phones I do have an incomplete version of Jyotish Tools for the Samsung Instinct which will be completed after the Android version.  Also the development system for the Instinct may make a BlackBerry Storm version possible.  There may be a remote possibility of an iPhone version as I may have access to an Apple Mac sometime soon.  The iPhone is the most popular of these devices however a bit more difficult to develop for since it requires learning a new language Objective C which fortunately is a bit like C with a thin "object" wrapper.  The Android and Sprint development uses Java so I have lots of common code between both versions.  Just the interface methods change.

Also since there was some interest in a version of MoonCast I plan to release it for phones possibly adding Panchang features.