Modern people use their smartphones more heavily than non-modern people, and it is not uncommon for them to operate their smartphones only with their thumbs. In other words, using a smartphone for a long period of time indirectly develops the thumb. This app measures the overall strength of your well-developed thumb and helps you reaffirm your own thumb strength.[Implementation guidelines]1. When conducting the test, the person taking the test must be in good health and take all possible precautions to prevent accidents.2. Perform the test exactly as prescribed and always use your thumb.3. Perform appropriate warm-up and organization exercises before and after the test.