En påmindelse i mobilen hjælper mig, og en notifikation fra appen minder mig også om mødet.

Those are the definite singular forms in Danish.

• en mobil → mobilen = the phone
• en app → appen = the app
• et møde → mødet = the meeting

Unlike English, Danish usually adds the definite article to the end of the noun instead of putting a separate word like the in front.

So:

• en notifikation fra appen = a notification from the app
• om mødet = about the meeting

Because påmindelse and notifikation are being introduced as indefinite things: a reminder, a notification.

But mobilen and appen are treated as specific/known:

• i mobilen = in/on the phone
• fra appen = from the app

This is very normal in Danish. The speaker is not talking about just any phone or app, but a specific one already understood from context.

They are similar, but not identical.

• påmindelse = reminder
  Something that helps you remember.
• notifikation = notification
  A message or alert, usually digital.

In this sentence, the idea is:

• a reminder in the phone helps
• a notification from the app also reminds the speaker about the meeting

So notifikation is more specifically a digital alert, while påmindelse is a broader word.

That is a very natural question, because English and Danish do not always use the same prepositions.

Here, i mobilen suggests something inside the phone/system, such as a reminder stored there. Danish can sometimes also use på mobilen in other contexts, especially when something is viewed or happens on the phone as a device.

So:

• i mobilen = more like in the phone / inside the phone
• på mobilen = often on the phone

In this sentence, i mobilen works well because a reminder is something contained within the phone.

Because fra means from and shows the source.

So:

• en notifikation fra appen = a notification from the app

The notification comes from the app, so fra is the natural preposition.

Because the two verbs work differently.

• hjælpe nogen = to help someone
• minde nogen om noget = to remind someone about/of something

So:

• hjælper mig = helps me
• minder mig om mødet = reminds me about the meeting

Notice that minde normally needs om before the thing being remembered:

• minde mig om mødet
• minde dig om aftalen
• minde os om det

This is just the standard Danish pattern for that verb.

Because mig is the object form of the pronoun, while jeg is the subject form.

• jeg = I
• mig = me

So:

• Jeg hjælper = I help
• det hjælper mig = it helps me

In the sentence, the speaker is receiving the action, so Danish uses mig.

That word order is natural Danish.

In main clauses, Danish usually keeps the finite verb early in the sentence, and short object pronouns like mig often come before adverbs such as også.

So this is normal:

• ... minder mig også om mødet

It means the notification also reminds the speaker about the meeting, in addition to the reminder in the phone helping.

If you move også, the emphasis can change. The sentence as written has a neutral, natural flow.

Because Danish often uses the definite form where English would use a possessive like my, especially when it is obvious whose thing is meant.

So Danish often prefers:

• mobilen instead of min mobil
• appen instead of min app

if the context already makes it clear.

Using min mobil is possible, but it would sound more explicitly possessive or more contrastive. In this sentence, mobilen sounds very natural.

Yes. In everyday Danish, mobil often means mobile phone / cell phone, just as English speakers often say phone instead of mobile phone.

So:

• mobil = common everyday word
• mobiltelefon = fuller, more formal word

Both are correct, but mobil is very common in normal speech.

The nouns are:

• en påmindelse — common gender
• en mobil — common gender
• en notifikation — common gender
• en app — common gender
• et møde — neuter

That is why the definite forms look like this:

• common gender: usually -en
  • mobilen
  • appen
• neuter: usually -et
  • mødet

Learning the noun together with en or et is the best habit, because the gender affects the definite form.