kono zisyoapuri wo tukatte mimasu.

You’re right: normal Japanese is usually written without spaces.

So the standard writing is:

この辞書アプリを使ってみます。

The spaces here are just for learners, to make the parts easier to see:

• この = this
• 辞書アプリ = dictionary app
• を = object marker
• 使ってみます = will try using

この means this, but it must come before a noun.

• この辞書アプリ = this dictionary app

By contrast:

• これ = this one / this thing

So you can say:

• この辞書アプリ = this dictionary app
• これは辞書アプリです = This is a dictionary app.

You cannot say これ辞書アプリ.

A useful pattern is:

• この + noun = this + noun
• その + noun = that + noun
• あの + noun = that + noun over there

It’s a compound noun, made from:

• 辞書 = dictionary
• アプリ = app

Together, 辞書アプリ means dictionary app.

Japanese often combines nouns like this very naturally. Similar examples:

• 日本語学校 = Japanese language school
• 電車通学 = commuting by train
• 英語辞典 = English dictionary

So yes, it functions as a single noun in the sentence.

を marks the direct object of the verb.

Here, the verb is 使う = to use, and the thing being used is:

• この辞書アプリ

So:

• この辞書アプリを使う = use this dictionary app

In other words, を tells you what is being used.

A few similar examples:

• 水を飲みます = drink water
• 本を読みます = read a book
• スマホを使います = use a smartphone

Because this sentence uses the pattern:

verb in て-form + みます

This pattern means try doing something.

So:

• 使います = use
• 使ってみます = try using

The て-form of 使う is 使って.

So the structure is:

• 使ってみます = will try using / am going to try using

This is a very common grammar pattern.

〜てみます means try doing something to see how it goes.

It often has the nuance of:

• giving something a try
• testing it out
• doing it experimentally
• seeing what happens

So この辞書アプリを使ってみます is not just I use this dictionary app. It means more like:

• I’ll try using this dictionary app.
• I’m going to give this dictionary app a try.

It suggests the speaker has not really used it yet, or is about to test it.

Historically, yes—it comes from 見る. But in this grammar pattern, it works more like an auxiliary expression and usually does not literally mean “see.”

So in:

• 食べてみます = try eating
• 読んでみます = try reading
• 使ってみます = try using

the みます part means try doing, not look.

That’s why it is often written in hiragana as みます rather than as 見ます, to show that it’s functioning grammatically.

みます is the polite form.

Compare:

• 使ってみる = try using it
• 使ってみます = try using it / I’ll try using it

So the sentence is polite and neutral in tone.

If you were speaking casually, you might say:

• この辞書アプリを使ってみる。
• この辞書アプリ、使ってみる。

Japanese does not separate present and future in the same way English does. The non-past form can mean either, depending on context.

So 使ってみます can mean:

• I try using it (less likely in isolation)
• I will try using it
• I’m going to try using it

In this sentence, the most natural interpretation is usually future/intention:

• I’ll try using this dictionary app.

Japanese often omits the subject when it is clear from context.

So this sentence does not explicitly say I, but in many situations it naturally means:

• I’ll try using this dictionary app.

Depending on context, it could theoretically refer to someone else, but without extra context, learners usually understand it as the speaker’s action.

This is very normal in Japanese. For example:

• 行きます。 = I’m going / I’ll go
• 食べました。 = I ate / have eaten

The subject is often understood rather than spoken.

Good question. The difference is mainly nuance.

• この辞書アプリを使います = I use / will use this dictionary app
• この辞書アプリを使ってみます = I’ll try using this dictionary app

So 使います sounds more direct and definite: the speaker will use it.

使ってみます adds the feeling of:

• trying it out
• testing it
• seeing whether it’s useful

If someone just downloaded a new app, 使ってみます is often more natural.

Not by itself, no. 使ってみます normally means something like I’ll try using it in polite speech.

If you want to say Let’s try using this dictionary app, a more natural form is:

• この辞書アプリを使ってみましょう。

〜ましょう is the usual let’s form.

So:

• 使ってみます = I’ll try using it
• 使ってみましょう = Let’s try using it

It’s the Japanese period.

• 。 = full stop / period
• 、 = comma

In casual texting, people often omit 。, but in normal written Japanese it is standard to include it.

So the complete sentence is:

この辞書アプリを使ってみます。