jmMemo AppL¸Rich media embeds (like YouTube) are coming, just a little more complicated than expected but it is being worked on. When it was crashing when you posted was that in a topic or a memo?
https://whatsonchain.com/tx/d6258d3c3cfb0b6c21894c765f1ac17fd8fdd64cea8a74f184783f29af27c6e5