FLStudio ASIO FLStudio ASIO has the advantage of being fully multi-client on most machines. This will allow you to hear the audio from FLStudio and other applications (such as YouTube, SoundCloud etc) at the same time ...
FLStudio includes a wide range of plugins: generators, tools and effects. However most of these are FLStudio format only. Which means they only work in FLStudio.
If they are available as a VST or AU format ...