I can't help but be reminded Mark Libermans's assessment of the app (http://languagelog.ldc.upenn.edu/nll/?p=10416).
Yes, the app is apparently quite insane.
It's classic Strunk & White nonsense, the idea that simpler (even to the point of being simplistic) is always, always, always better, founded on the unfounded idea that removing words is the only way to linguistic correctness.
http://chronicle.com/article/50-Years-of-Stupid-Grammar/2549...