How do I edit/delete the client, subscription or publication?

Long press on them

Can I use wildcards in the subscription topic?

Yes, enjoy the wildcards!

Can I use wildcards in the publication topic?

No

What is the "numeric" property used for?

If your subscription values are numeric, they will be displayed in a line chart.

Does the chart update in real time?

Try it yourself! ;)

How do I copy the messages?

Click on them

Why do my widgets lost their status when I re-open the app?

When the app is started, it does not know the current value of the topics. Because the values might be changed by other publishers when the app is not connected to the broker. That's why you see the n/a value and the widgets are at their default state.

I want to keep the status of my widget. Is it possible to do that?

You can make the values retained (select "Retained" in the publication configuration). So the next time you start the app, it can receive the last value and update the widget's status. To delete the retained value, publish an empty value to the topic.