Obvious flaws. Not reliable.

I may not be an expert, but I can tell this app was not reviewed thoroughly enough. In one question, I am sure I am correct because the phrase is "After dinner, I wash (blank) dishes."

It says that "the" is wrong and the correct response is "an", so I wash an dishes?

If I rely on this app, I am going to learn the wrong things are right.

whatever_whenever about Practice English Grammar, v0.9.6