Put in the work and it’s worth it.
Excellent for help with routine, self settling, a workable sleep/nap schedule and evidence/science-based approach to baby sleep. The app could be a lot more intuitive with a personalised dashboard based on data you input in real time. There is also a LOT to read, with a high level of understanding required to distinguish the subtle stages of the soothing and settling methods. Also the reading is not really optional - you have to invest if you want to get it right. So not sure an app is the best format. I also think the peer-led sleep consultants are largely good but you do end up getting repeat advice and lots of cut and past answers rather than really individualised responses. Some are better than others. And usually by the time they reply you’ve figured it out already.
But: we did follow it, read everything, ask questions and persevere. And we have seen a dramatic improvement in our baby’s sleep. She learned to self-settle within 2-3 days. Getting the naps right has taken weeks and the lunch nap still goes awry quite a lot. But she is linking those sleep cycles and has slept through the night (7pm-7am) in 3 occasions, with only 1wake on most nights - and this was through the 4mth sleep regression and some intense teething. So do it, but expect it to be hard work. It’s on you to make it work! Good luck!