Left: water 氵, right: morning 朝 - BETTER: lake 湖, having the part: "old 古" both normal and upside-down to show changing directions of the tides. The lake with changing directions stands for: seawater & tides.
Left: mouth 口, right: morning 朝 (= sunrise [= sun 日 rises between plants 艹] and the moon 月 is still there.) This mouth early in the morning cannot but ridicule sneer.
Radicals are shown here that are similar either in appearance or meaning.
The app has many other functions, such as character selection according to difficulty, practice programs, handwriting recognition and success statistics!
(The sun 
