FXPesa is axctually a trading name, the real company behind it is UK based Equity Group (EGM Securities).
EGM Securities has gotten a licrnse from CMA Kenya to operate the FXPesa brand name so yes they are 100% legit.
FXPesa is also authorized by the CMA Kenya to offer Nairobi Stock Exchange Derivatives (Futures on NSE stocks).
However, where some people have a problem with FXPEsa is in their spread which I think is high and not too transparent.
Some also complain about their customer service. It depends on who you ask, for me they are okay but you need to be an experienced trader before using them.