Softorino has released WALTR, a Mac OS X app that uploads any video or audio format from your Mac onto an iPhone or iPad.
The app lets you import and watch MKV, AVI, MP4 videos, or any audio format, on your iDevice without having to convert the files first. Launch WALTR, connect your device, drag a movie or audio onto it, and the app automatically starts uploading into your iPad or iPhone. You can then access the files from your native iOS Music and Videos apps.
WALTR requires Mac OS X 10.9 or higher and any device with iOS 5 and above. You can download (http://www.softorino.com/waltr) a free, 14-day demo. A lifetime single user license is normally US$29.95, but WALTR is available for $14.95 for seven days.