In Preachit 4.1 it is possible to output details in a JSON array that can then be used by apps and code outside of your Joomla site. It is fairly simple to activate this. If you are using non-sef urls then simply add '&format=JSON' to the url as below:
index.php?option=com_preachit&view=studylist&format=JSON
If you are using sef urls then you will need to add '?format=JSON' at the end of the url as below:
sermons/messagelist?format=JSON
All Preachit views will produce JSON output if activated in this way. You external app or code can then use the information in the JSON array.