From Macupdate's page:
iVideo Converter is currently unavailable. The developer has requested that MacUpdate no longer link to iVideo Converter, as changes in PayPal fees have made the app less viable to develop so it can no longer be purchased. This situation might change in the future, but no solution is expected short-term.
The last version released was 2.1.7 and can't be downloaded from Macupdate or Versiontracker. iVideo Converter's site is down and if you purchased it their contacts page is gone as well.
As far as alternatives go there is still VisualHub - if you can find it.
Handbrake - but only outputs a few formats.
iSquint - Discontinued.
Or some of the on-again, off-again VisualHub replacements, like FilmRedux, Redux Encoder, VideoVangelist (discontinued), etc...
Then there are other converters out there with hit-or-miss reviews like Episode, Video Monkey, or others.
And there's also MEncoder if you like to type a lot. And iSkySoft's simply named "Video Converter".
For clients I find myself using Apple's Compressor and Adobe's Media Encoder a lot. Oh, and Mpeg Streamclip for the odd Flip HD video client's love for me to "incorporate" into their "vision". Gah...when they're sitting watching me work I make them watch FCP render Flip .mp4's because I'm evil like that.