Due to the pace of our initial launch, we were left with a significant amount of "design debt". Screens that did not align with our visual system, behaviors and patterns that did not meet Google's Material Design standards.
Getting these updates on the roadmap was a challenge. There will always be a new feature to build, another bug to squash.
I met with the Android engineering team. They were anxious to make improvements, but not at the expense of productivity. So, I recruited a Material Design Taskforce... a black-ops team of deadly Android developers.
I performed an audit of the Android app and created a backlog of small, manageable tasks. I got estimates and prioritized tasks by performing a cost benefit analysis.
During a sprint there are naturally occurring periods of downtime. When a lull arises, developers pull a task from the backlog. Once the task is complete it is placed on a separate branch of the app. When enough tasks are completed, the branch is merged and released to the public.
Our product team is aware of our task force. As long as deliverables are met, they love seeing us roll out visual improvements.