Koon Khmer

To Rama

Regarding your question about the non-supported plug-in; the problem is only indirectly caused by the youtube-bbcode.
BBCode (Bulletin Board Code) is a lightweight markup language. The real problem is that the custom Youtube BBCode makes use of Adobe Flash. As of Android Jelly Bean (Android 4.1), Adobe stopped all support of Flash.

IMO there are a few alternatives: introduce Adobe AIR or HTML5 from my side, install/use an alternative browser (eg ) from your side.
I just made a successful test with Dolphin from Android KitKat.

I'll do some research from my side and meanwhile I'll also post the link to the Youtube website.

Kind Regards

Test video (with Flash)

Test video (without Flash)

Update:

From now on you will notice (in your reply or new post window) 2 custom Youtube BBCodes; youtube and youtube2.
youtube makes use of Flash; youtube2 doesn't (HTML5). This means that youtube2 should normally work on Android and iOS without making any changes.

ATM the only remaining problem is that 'youtube' only needs the video-code (eg.HL1UzIK-flA) whereas youtube2 needs the youtu.be link (eg.https://youtu.be/HL1UzIK-flA).
You'll also notice this when you move your mouse pointer of the buttons.

As such no problem; but sometimes Youtube makes also use of youtube.com links which won't work in youtube2.

I'll do some additional research on that.
Meanwhile I'd strongly suggest to use the new youtube2 BBCode. However I'll keep both till I find a final solution.

To be continued.