Which direction are you going?
If Flashcards Deluxe to Anki, then you'll want to export your deck from within Flashcards Deluxe:
Tap Edit, tap deck, Export/Share. You have some options. Export to Dropbox or Google Drive if possible. Otherwise, export to "App Server" (you'll make up a "deck code"), then go to my "export" page to grab your text and media, at:
http://orangeorapple.com/Flashcards/Export.aspx. In this case, you can optionally also export by email to get text in Excel file.
At this point, I don't know how to get into Anki... you'll have to ask on their boards, but you should have all the file data you need.
There's not going to be any automatic conversion either way, but both apps can import and export, you'll just need to manually reformat a bit.
If you are going to Flashcards Deluxe, below is the info I have:
The only way I know how to transfer data from Anki is with the help of the desktop version of Anki to export.
Open the deck in your desktop version of Anki. (If you need to, export the deck from the mobile app as an apkg file and import that to the desktop version.)
In Anki desktop, export the deck (File > Export) using format "Notes in plain text".
Copy paste that into excel and cleanup if needed so you have a nice two-column list of questions and answer.
If you have picture/sound names, you'll want to keep just the file names (and remove Anki's extra stuff). (You can use a formula to do this.) Save as .xslx or .txt file.
Now you’ll want the media, if you need to transfer that. You need to find where Anki stores it. On PC, try:
\My Documents\Anki\User 1\collection.mediaAnother way to get the media is to rename the .apkg file to .zip, unzip, and look for the media in a "collection.media" folder.
Now you should have text and media and can transfer to Flashcards Deluxe using one of the transfer methods (my website, Dropbox, Google Drive).
http://orangeorapple.com/Flashcards/