iMovie for OS X removed from OS X? I had already installed iMovie on my Mac. Now after some months I wanted to create a new movie, but I couldn't find iMovie in OS X again.

When I look in the App Store I can see iMovie available now for $15.

Now I am very confused. Could it really be that Apple uninstalled iMovie and now I have to pay for it? Or is this a different version?
Apps don't disappear automatically. If you have iMovie '11 (version 9.x, gold + dark grey icon), the Mac AppStore will show the current version of iMovie (version 10.x, purple-coloured icon) as a new item because Apple charges for major version upgrades (e.g., version 9.x to 10.x), unless the user has a voucher from purchasing a new Mac.