Pro pilot is a worthy contender. I used their notes on the IPad and for the most part it's pretty good, similar to Bristol. Believe it's also in 3 modules. Few posts about Pro Pilot on the forum so have a search. Don't think you can go wrong with Bristol either, they have good notes some of which I also used.
I have only heard bad things about CATS from people I have met who used them but can't vouch from my own experience.
As pointed out most of the info you are after is in Lasors or the new EASA licensing CAP 804 and off course on this forum and google.