I'm planning to purchase this plugin to use it on a site in French and I wonder if I can have it in different language instead of English?
The plugin only comes with English and German, but it is compatible with WPML if you want to use that. Other than that you can always translate the frontend via the settings, labels tab. If you need the backend language to change you can also edit the .po / .mo files with a program like poedit. Please do not change the name of the plugin as that will create issues.