From top: grass, plant 艹, 怱 (= hurry 匆 and heart 心) [hurry 匆 = When packing the suitcase, the wrapped 勹 long things ノノ (= pants) got wrinkles because I was in a hurry)]
Mnemonic
The plant that is in a hurry (= grows quickly) and is closest to my heart is the leek.
The app has many other functions, such as character selection according to difficulty, practice programs, handwriting recognition and success statistics!