Oh, some multimedia app such as converter, player, burner.
You need to be careful. There are a lot of media converters out there. Some are free, but many charge a fee. However, they are rip-offs. Your
Quicktime Player (
Quicktime X) or the free
Handbrake will handle your conversion needs.
Before the
Mac App Store, there were two major websites to search for Mac software, c|net's Download.com, which also operated TechTracker.com, and MacUpdate.com. These sites did not store files on their own servers. They merely provided information and links to software on developers' servers. Generally, these sites also provided links to the developers' websites so that you could explore for yourself before deciding to download.
MacUpdate.com is now transitioning itself to a subscription service that conceals the URL of its client developers. However, you don't have to subscribe, but may continue to use its links to software that you want to download. It is still a useful site that lists just about every Mac software title that is available.
c|net is another matter. It now wraps many of its listed titles in downloaders that download .dmg image files or .zip from the developers' website. These downloaders also install adware on your computer unless you affirmatively refuse permission to install the adware.
Boo-Hiss to c|net.
I almost forgot. There are websites that host software for certain target audiences such as scientists and engineers. There are also sites that host open source or freeware. Often this software is ported from generic Unix. Also, some of may be rather old.