In this post there is a description how to get the Data from the Wunderlist SQLite Database with a Firefox extension. With the new version the location of the database file has changed.
Excerpt from the Wunderlist Support site:
On Mac if you have the App Store version of Wunderlist 2:
/Users/yourname/Library/Containers/com.wunderkinder.wunderlistdesktop/
Data/Library/Application\ Support/WunderlistIf you have the version downloaded from www.6wunderkinder.com:
/Users/yourname/Library/Application Support/Wunderlist/The name of the file is WKmodel.sqlite
If you have the Windows App installed:
It is located in the users roaming profile: c:\Users\Username\AppData\Roaming\6Wunderkinder\
Wunderlist\Wunderlist.dat
An updated SQL query for SQLite is available for download as a textfile. The query just gets the data without the new subtasks:
Select T.ZTITLE,T.ZNOTE,datetime(T.ZCOMPLETEDAT,’unixepoch‘),L.ZTITLE From ZRESOURCE AS T INNER JOIN ZRESOURCE AS L ON L.Z_PK = T.ZTASKLIST order by L.ZTITLE