The tool is not worth the money :-(
At least on my MBP M3 with Sonoma, the statistics are simply wrong.
Wattagio does not recognise that the charging cable is connected or disconnected during sleep mode. With the MBP's frequent wake-up cycles, this should be feasible.
Tonight, according to Wattagio, my MBP worked all night, although other apps like SleepAid disagree.
Spontaneously, Wattagio keeps saying I'm charging - all in all, you don't need such unreliable statistics ... too bad
And worst of all - the developer doesn't even respond to enquiries :-(