The first 10 minutes, I really thought what a wonderful plot and so much potential the director has. The interview scene was well crafted .The Ouija app was a new and beautiful idea. But, how did the director use it? He completely wasted that idea. A Korean director would have capitalised with such wonderful idea in hand. You showed that the first ghost connected with the app, and then what happened, no information about it. It was never brought up anywhere later in the movie. There were many jump care screens which were brilliantly made. The kitchen scare scenes were really good... You were able to do that without much make up or CGI.
It's obvious this is a low budget movie. You've to spend time on a tight screenplay if you want to make a masterpiece with a limited budget. And, he was there at one moment, but suddenly he drops the ball.
If the ghosts are so powerful and can kill by itself, why did it involve the hero in the killing in first place? Was the motive of this even explained? And why was it not able to use the same powers to do the last kill? Just the director ran out of ideas is it?