Create your OWN Appending Comments in PowerApps 

Want to have a comments section in your Power App and also keep all the old comments plus the user name? This was a requirement in one of my projects.
We use a SharePoint multi-line text field to store the comment data. We even add our own HTML to bolden our name an italic the comments.
My name is Andrew Hess and this is a Power Apps tutorial.
New Comment, on One Screen:
Patch(
MyComments,
{
Title: TextInput2.Text,
theComments: Now() & " - " & "&ltb&gt" & User().FullName & "&lt/b&gt" & " " & "&lti&gt" & RichTextEditor1.HtmlText & "&lt/i&gt"
}
Patch Comment, on One Screen:
Patch(
MyComments,
Gallery1.Selected,
{theComments: Now() & " - " & "&ltb&gt" & User().FullName & "&lt/b&gt" & " " & "&lti&gt" & RichTextEditor1.HtmlText & "&lt/i&gt" & HtmlText1.HtmlText}
)
When using 2 screens, you can define a variable to tell the screen whether you are in Edit Mode or in New Mode.
Combined Patch Comments Button on both Screens:
If(
varNewForm,
Patch(
MyComments,
{
Title: TextInput2.Text,
theComments: Now() & " - " & "&ltb&gt" & User().FullName & "&lt/b&gt" & " " & "&lti&gt" & RichTextEditor1.HtmlText & "&lt/i&gt"
}
);Navigate(Screen1,Fade);,
Patch(
MyComments,
Gallery1.Selected,
{theComments: Now() & " - " & "&ltb&gt" & User().FullName & "&lt/b&gt" & " " & "&lti&gt" & RichTextEditor1.HtmlText & "&lt/i&gt" & HtmlText1.HtmlText}
)
);
Chapters:
0:00 Introduction
1:19 SharePoint with Comments
2:57 Starting our Power App
4:35 Writing the Patch Statement
7:32 Writing our own HTML in our Comment
10:55 Writing a new comment using 1 Screen
13:44 Adding a Second Screen to our Power App
15:53 If A New Form Then "Do This"
18:00 Using Patch for our 2 Screen Comments
20:10 Making Title and Comments Required