anonymous555, there were 7 volumes of the Igros Moshe put out by R’ Moshe himself. An 8th volume was put out after he passed away that was not prepared by him. Many people hold that the teshuvos written there need to be taken with a grain of salt, as they weren’t selected by R’ Moshe himself for publication.
In the shul where my parents daven, the only Yad Moshe they have is an English version. Yes, I do know how to use it. I don’t even know if there’s a Hebrew version (I assume there is), but I did know how to use the one the shul had, which was in English.