The forward, 22, has signed an initial one-year contract with the Shrimpers after impressing in a behind-closed-doors match against Fulham on Tuesday.
"English football was always my favourite when I was growing up so I'm looking forward to showing the fans what I can do," he said.
"I haven't had a proper pre-season with a squad but I've done a lot of running back home in France to keep fit so I don't believe that will prove too much of a problem.
"The language will be a barrier to start with but I'm going to learn as quickly as possible."