I got an email from Izotope today telling me that Ozone Elements is available free for a limited time. This is version 8. They are getting ready to release version 9, so I suppose they are hoping that people will try version 8 and feel the urge to upgrade when they dangle an attractive price in front of existing users. The normal price is $129, so $0 is a pretty good deal

Ozone Elements is probably the most useful plug-in I have ever installed. It makes mastering easy and produces a great sound without you really needing to be an expert. I normally find that choosing a preset is enough without any adjustment. I was using version 7 and have just downloaded 8. It has quite a lot more features. Especially useful, in my opinion, is the option of selecting between mastering for streaming and for CD. Basically, the CD setting maximizes the volume while the streaming setting applies the standard -14 LUFS for loudness, used by  Spotify, etc. I used to have to do this using a separate plug-in called YouLean Loudness Meter (also really good), but it's great and far quicker to be able to do this automatically when you master. If you are uploading a single, you can actually set the loudness higher and Spotify will automatically reduce it to -14 LUFS, but if you are uploading an album, it's important to have all tracks the same volume when you upload them. Spotify's algorithm will not adjust them individually, so a listener would have to keep adjusting the volume on his/her phone.