Platform Events are meant for integration with other platforms outside of Salesforce. However, you could also define apex triggers on platform events, this helps in certain situations like below

• If you want to execute the apex as another user (with elevated access) other than the running/current user, even though apex triggers run as system user the running user is still the user who initiated the transaction
• Since platform events run asynchronously, these run on a separate thread and help as an alternative when you run into governor limits on an object apex trigger

Sample Use Case: Opportunity trigger is running into CPU timeout exception, you are moving automation's that run after Opportunity stage moves to Closed Won into a asynchronous operation to avoid CPU timeout.

STEP 1: Create a platform Event:

Step 2: Create a custom field

Create a custom field on the platform event to store the Opportunity ID 

Step 3: Create the apex trigger

Step 4: Call the platform event trigger by simply creating a record from the Opportunity trigger or a flow

Note: The platform event object needs to be granted access to the profiles that will be creating the event record, FLS is not applicable

FORM_FACOTR

You can use the FORM_FACTOR to determine the device type, however while experimenting this seems to work only in mobile app and not a mobile browser.

To use this module you need to import it like below.

import FORM_FACTOR from '@salesforce/client/formFactor'

The FORM_FACTOR can have below values based on the type of the device.

• Large - If the device is a desktop.
• Medium - If the device is a tablet.
• Small - A phone client

navigator.userAgent 

This seems to work both with mobile apps and the mobile browser. Add the below method to your LWC JS file

 Found this article on the Salesforce Knowledge base. However, this method does not work and not sure if the article is even accurate. The last part of the article asks to perform a Update on the 'EmailRelation' object but without a Id field mapped, so i believe the article needs to be checked for accuracy.

The steps below are the ones that worked for me and happy to share it here. Before looking at the steps, some points to note about uploading Email Messages via the data loader.

• The Email Message object has a Status field. This is set to '5' (Draft) by default. The record is only update-able as long as it is in Draft status.
• Uploading to this object will not send out an actual email.
  
• If the uploading CSV file has a single error, all records fail in the operation. I experienced this for the EmailMessage object and the EmailRelation object. One of the records in the relation object pointed to a merged contact and my entire file failed with the same error for all rows. On removing that particular record, the file uploaded successfully.

STEP 1: