File Converter Free promises to convert just about any type of file on your iOS device into a comparable file, and for the most part it delivers on that promise. The issues we experienced were largely with upload and download time -- as it appears the conversion process takes place on the developer's servers. This is both a good and bad thing. It's good because it opens up the number of options. It's bad, however, because the conversion process is completely reliant on the speed of your device, the server, and your network connection.
After installing the app, we chose a file from our library -- a standard 6.5MB image file -- and converted it into a comparable format (BMP). The file was uploaded to the server, converted, and downloaded back to the device. While the file looked exactly as it should and the new format was spot on (and ready to e-mail or send through another file-sharing app), the entire process took about two and a half minutes. For an image, this is fine, but for larger files, it's easy to see this process becoming an issue. With a warning onscreen to not let your device go to sleep, lest there be conversion errors, performance could become an issue.
For small files, quick conversions on the fly, or space reduction before sending a file to a friend, File Converter Free works quite well. You are more likely to continue converting large files and videos on your desktop, however, due to the limitations on speed and the warnings about leaving your device to run the conversion, unattended.