During testing of Image Resizer on Yosemite I noticed an issue with the app not detecting retina displays. This problem causes the retina images to be created at the wrong dimensions.
Due to this problem I have decided to remove Image Resizer from the Mac App Store until the new version is ready for release.
If you notice this problem yourself a temporary fix is to find Image Resizer.app in your Applications folder, right click the file then click on “Get Info”. Under the General section put a tick next to “Open in Low Resolution”.
I am already working on a new version which adds new features and will include this bug fix. The new version should be ready for release end of November 2014.