Is it possible to convert a FF Jetpack extension to a chrome's one? I've read something about wrappers but I don't know if they have already implemented one.
Thank you
No. In general, extensions based on the Firefox Add-on SDK are more powerful - chrome authority gives them access to all browser internals, a level of access that Chrome extensions simply don't have. Even if you only look at the API provided by the SDK, it is different enough from Chrome's extension API that any kind of generic conversion is impossible. However, often you can convert an extension manually but reimplementing the necessary parts.