1. Does Caissa chess implement [http://en.wikipedia.org/wiki/En_passant "en passant" rule] ? 
     Yes Caissa chess implements it, as well as any other chess rule known to [http://www.fide.com/ FIDE].[[br]]
     Please check [http://youtube.com/watch?v=ZUJMT8AsFZ4 our "en passant" demo] on youtube. 
 2. What is the strength level of Caissa's chess engine ? 
     We estimate the engine is capable of rendering decisions at 1900-2000 [http://en.wikipedia.org/wiki/Elo_rating_system#Elo.27s_rating_system_model ELO] level. This engine was designed to perform on mobile platform, with power efficiency in mind. We are working on [http://en.wikipedia.org/wiki/Candidate_Master CM] mode, which will make Caissa significantly stronger.