In reply to:...
There are two separate Workflows which are actually pretty simple - one for each action.
The like flow is intended to be triggered from Safari so is set up an Action Extension. When I'm on a page I want to like I go to Share > Run Workflow and select the 'Post a Like' flow. This takes the URL as the input, asks me to comment then simply posts to WordPress with the URL passed as a custom field.
The plugin then takes over and uses the custom field to add a properly formatted link to the start of the post.
For my own benefit, the flow also gets the page name and displays it just so I can check what is going to show in the post, but that's not essential and doesn't affect the actual process.
The Reply flow is also an Action Extension but acts a little differently.
It accepts text as the main input so I write the reply in Drafts, share it using the flow which then prompts me for the URL I am replying to and passes it as a custom field.
Again, the plugin takes over and adds the reply link to the start of the post content.
And that's how this post was published.