The CCleaner health check page wants me to upgrade to premium but I cannot find out anything about what that is. Can anyone help?
There is CCleaner Free, CCleaner Professional, CCleaner Pro Plus, and CCleaner Premium.
Free is a basic cleaner with some of the more advanced functions/tools not enabled.
Professional has all the fufunctions and tools enabled. It is licenced for 1-device and you buy it for either PC, Mac, Android, or iOS.
Pro Plus is the same as Pro. but licenced for 3-devices, any mix of PC, Mac, or Android. (Not iOS yet).
It also let’s you use the same key to register the other Piriform softwares (Speccy, Defraggler, Recuva) as Pro on PCs
Premium is the same again, but for any mix of 5-devices, and also licences Kamo on those devices if they are PCs.
The CCleaner in all paid-for cases is CCleaner Pro - the Plus, and Premiun licences just licence it for use on multiple machines.