Progress vs. targets:
- % increase/decrease in new editors (# of editors who registered and made an edit with Android app in first 30 days)
- % increase/decrease in editor retention (of those new editors, how many edited with Android app again in second 30 days)
- % increase/decrease in edit rate (avg. # edits/day)
Across all languages. For simplicity, compare July 2018 (android app edit change tag became available on 2018-06-18) vs May/June 2019.