Watch Chinese characters on your Apple Watch or iPhone. This app contains the most common 150 Chinese characters (together with their pinyin pronunciations and a basic definition) and allows you to set each character to appear on your screen for 2 to 20 seconds. This way, you can learn and memorise each of these characters by watching them play over and over again. Running this on your Apple Watch allows you to inconspicuously study from the corner of your eye. You may also play this in your iPhone alone if you wish.
NB: Please understand that this app contains only the most common Chinese characters, and definitions given are also very elementary.