Doremisoft Mac Flip Video Converter is a commercial video converter. It can be used to convert videos recorded by popular Flip camcorders into other formats. I couldn't find an accurate mention of the supported input formats, but the developer's description seems to indicate that files recorded with the Flip Ultra, Flip Mino, Flip Ultra HD, Flip Mino HD and Flip SlideHD can be converted with this app. I tried opening MKV files and they weren't supported. AVI files worked just fine. As far as output format support goes, this converter seems to support the most popular ones, including H.264, MPEG-4, MOV, AVI, and even MKV.
The graphical user interface is similar to that of most other commercial converters. You have a big space where the files in your conversion queue are listed, a video player to play your videos before converting them and a drop-down menu with all the supported output conversion formats and profiles.
This app comes with a video editor that allows you to trim and crop your video and to adjust some of its properties.
While testing, I converted a sample AVI file into MP4 and I didn't experience any problems. The resulting file looked almost identical to the source one.