In fact, we often need time keeping. While studying, doing sports, reading a book, etc. But we don't always have a stopwatch with us. But remember, your phone is always with you.
You can do a lot of things with your phone. From playing games to quitting texting or even shopping, you can do most things with your phone in one click. One thing you can do with your phone is time keeping!
So time matters. You have to spend well!