Hi! The formula is tricky to understand, it's a workaround that allows us to access the data from the previous period. You would need to write down the definition of rollavg to understand why I multiply by two (essentially it means instead of average, I get the sum of the two periods.)

Lifecycle pulse has some similarity, but is focussed on the ratio of users becoming active vs inactive. Growth rate focusses on the the ratio of actives one period to the next.