Ver2.7: The bar chart is added.
Ver2.6: fix problems for Android Oreo.
Ver2.5: fix problems for Android O.
Ver2.4: fix problems.
Ver2.3: Bug fix.
Ver2.2: Bug fix.
Ver2.1: Bug fix.
Ver2.0: Appearance was slightly changed because of using latest parts of Android.
Older version of widget is no longer supported. Replace it to new one if you use it.