WALTR PRO allows you to transfer the files to 3d party apps.

Here is the list of supported applications:

1. Documents
2. VLC
3. Infuse
4. PlayerXtreme
5. PDF Expert
6. GoodReader
7. Kindle
8. VOX
9. FLAC Player+
10. AVplayer
11. PDFpen
12. PDF Pro 3
13. Adobe Acrobat
14. iMovie
15. Pages
16. Keynote
17. Numbers
18. ComicFlow
19. iComics
20. Files by WALTR