Thorough and concise
I think this app is good for refreshing yourself with the names of terms that you probably have already heard before for, but need to brush up on. I think the app needs to have more categories added for the paid version though. Also the pronunciations or tones of the voice recordings are sometimes incorrect even if though the pinyin seems to always be correct. For example, 行 is read as xing when it's supposed to be read as hang in one place (this character has two readings)