A very important tool for SWF manipulation is a way to debug them and to have a look at the bytecode. Dump is a tool that does nothing else but listing all SWF Tags and ABC files the way Apparat represents them internally.
I know that there are a lot of other tools out there. swfdump and abcdump are great already. I have used swfdump from the Flex SDK before. But I dislike how they represent namespaces and the fact that not all properties are always shown. Dump is simple. It lists everything and uses the naming form the avm2overview.pdf.