Hiragana having it up my watch

Firstly, this app has been specially created with people who not only are big fan of Apple Watch but also plan to visit Japan or are interested in Hiragana (ひらがな) letters in particular and also wonder how to write them. And, you can also select between 2 languages, such as English or Japanese, at the bottom of the page.
In Japan, we are taught how to read and write Hiragana during the first grade (Age 6) of elementary school. Once you got it, you would be able to write a letter or mail in Japanese however the face of the mail, that written in Japanese used only Hiragana, would be unnatural. The reason why it seems to be bizarre is that we are supposed to use not only Hiragana letters but also Katakana and Kanji letters.
Secondly, on this app, there are two ways to learn Hiragana letters on the app. The one is to practice a single Hiragana letter that has no meaning, which is focused on how to write and how to pronounce each letter. The other is to practice Japanese word written in Hiragana letters, which is focused on how to compose these letters to build a meaningful Japanese word.
As you see, a single Hiragana letter has no meaning. Hiragana letters are only supposed to make sense if they are composed to build a Japanese word. On the practice page of Japanese word, you can see both English word and Japanese word written in Hiragana letters.

Let’s say, if you want to say that you like summer.　In English, it would be...I like summer.
If you only use Hiragana letters to write this, it would be...
(A) わたし　は　なつ　が　すき [watasi wa natu ga suki].
Then, if you replace some words with Kanji character, it would be...
(B) 私　は　夏　が　好き [watasi wa natu ga suki].

Even though the face of (B) is different from the face of (A), all of them are exactly the same meaning. What is difference between (A) and (B) is that 2 words are replace to Kanji characters. If you see a sentence (B), you will notice that there are still some Hiragana letters left and wonder why these letters are still written in Hiragana. The answer to your question is that these are the letters that are not replaceable to Kanji letters.

- わたし or 私, means [ I ].
- なつ, means [ summer ].
- すき, means [ like ].

Lastly, I would like you to feel like having a bit of Hiragana letters up your Apple Watch, as the saying goes, "have something up one's sleeve."