100th Post

Finally I reached this 100th post.

Since I have posted my journals on Lang-8 every day, today is day 100.

However, I still make the same mistakes (especially about "a" and "the") repeatedly.

I think making mistakes repeatedly is rude to those who corrected my posts.
(I'm real sorry.)

Reviewing repeatedly every day is very important, however, it is also difficult.

I'm considering a development of software that we can review a few our posts selected randomly.

For the time being, I will review my posts in order.

100回目の投稿

ついに100回目の投稿になりました。

lang-8を始めてから毎日投稿しいていたので、これで100日目ということになります。

しかし、私は未だに間違い（特に a と the の間違えなど）を繰り返してしまいます。

添削して頂いた部分を繰り返し間違えることは、添削して頂いた方に失礼なことだと思います。（本当にすみません。）

毎日復習をすることは非常に大事なことですが、続けるのは大変です。

私は今、過去の投稿からランダムに幾つかの記事を選択して、その記事を復習できるようなソフトウェアの開発を検討しています。

一先ず今日は、過去にして頂いた添削を順番に読んで復習をしようと思います。

• Finally I reached this 100th post.
• This sentence is perfect! No correction needed!

• Since I have posted my journals on Lang-8 every day, today is day 100.
• Since I started Lang-8, I have posted my journals on Lang-8 every day, and today is day 100.

• However, I still make the same mistakes (especially about "a" and "the") repeatedly.
• This sentence is perfect! No correction needed!

• I think making mistakes repeatedly is rude to those who corrected my posts.
• This sentence is perfect! No correction needed!

• (I'm real sorry.)
• This sentence is perfect! No correction needed!

• Reviewing repeatedly every day is very important, however, it is also difficult.
• This sentence is perfect! No correction needed!

• I'm considering a development of software that we can review a few our posts selected randomly.
• I'm considering a development of software so that we can review a few of our posts selected randomly.

• For the time being, I will review my posts in order.
• This sentence is perfect! No correction needed!

No need to apologize--articles are hard when you're not used to them. Besides, you didn't make any mistakes with articles in this post. :)

Congratulations on 100 posts! You're doing extremely well.

• Since I have posted my journals on Lang-8 every day, today is day 100.
• Since I have posted my journals on Lang-8 every day, today is day 100.

  This structure is a little off. You cannot say "today is day 100" because it is not a direct result of your posting journals every day. If you only posted journals once a week, you could still eventually post 100 journals. Also, even if you took a day or two off, we could still say that today is your 100th day of using Lang-8.
  
  You could say:
  I have posted my journals on Lang-8 every day; today is day 100.

It is not rude to make mistakes! Not as long as you are trying. The difference between "a" and "the" is also very difficult because Japanese does not have anything like this. I don't even know how to explain the difference to Japanese speakers sometimes.

• Finally I reached this 100th post.
• I have finally reached my 100th post!!!!!!!!!!!!!!!!!!!!!!!!1

  It's exciting, right?!

• Since I have posted my journals on Lang-8 every day, today is day 100.
• Since I started on Lang-8, I have posted my journals every day and today is the 100th day.

• However, I still make the same mistakes (especially about "a" and "the") repeatedly.
• However, I still make the same mistakes (especially when using "a" and "the") repeatedly.

• I think making mistakes repeatedly is rude to those who corrected my posts.
• I think making the same mistakes over again is rude to those who have corrected my posts in the past.

• (I'm real sorry.)
• (I'm real sorry.) or "I'm really sorry"

  Both of these sentences are okay. The difference just depends on your style of speaking.

• Reviewing repeatedly every day is very important, however, it is also difficult.
• Reviewing repeatedly every day is very important, but also difficult.

  "Reviewing repeatedly every day" is not necessarily wrong. But it means that you are trying to review several times in one day, every day.

• I'm considering a development of software that we can review a few our posts selected randomly.
• I'm considering developing a software that will allow us to review old posts selected at random.

• For the time being, I will review my posts in order.
• This sentence is perfect! No correction needed!

Your idea sounds really cool. I am also going through and reviewing my old posts in order. There is no other way for me to mark the ones I have already reviewed so I am just adding numbers to my titles.
Good luck with your studies.