Apple - iPad app with variable speed video playback?
I built Swift Player for iPhone and iPad that will allow you to change (speed up) the playback speed of video and audio from the device or even directly from websites like YouTube, etc.
You can find out more information on the product's website.
Note: This is a product that I have developed.
I can't find any playback app on the iPad with the exact 1.7 ratio...
However, Azul for iPad (app store link) has 1.5 and 1.75 playback ratios. They even say in their site blurb that it's good for fast reviewing of lectures.
Reviews are excellent and integration with Mail and Dropbox is there, as well as a very comprehensive codec list