At selecting a thread, browserAction popup window is opened automatically.
For the above action,
1) I added listener to thread tree last child in implementation.js.
2) I added listener to browser on activation of any tab in background.js.

June 20th 2021.

From Sungho Hwang.

Version 1.9

This version is to open browserAction popup window automatically.
I added async function at click event listener of thread tree last child to await recognition of thread tree.

April 23rd 2021.

From Sungho Hwang.

Version 1.6.

I fixed browserAction popup window to open it automatically using typeof and changing thread tree name uniquely.

April 1st 2021.

From Sungho Hwang.

Version. 1.3.

1) This add-on is to Confirm conversions of e-mail to event and task at selecting thread tree children and save them.

March 30th 2021.

From Sungho Hwang.