It is important to keep the team updated and involved as much as possible with the progress of the app. As people can get entrenched in their own specific work projects, it is your job to keep the team together and informed. Sharing positive statistics and positive feedback helps validate the work of your team. Too often the workers who do not interact with customers never hear the praise they deserve.
As a product manager you should send out basic analytical stats every week about the status of the app. Sharing information on downloads, revenue, important KPIs, advertising campaigns, and other marketing efforts. This will hold you more accountable and keep the team informed.
Hold a consistent meeting (weekly, bi-weekly, or monthly) to discuss product updates, summarize the previous work timeframe, and decide what needs to be improved. Keep the floor open and allow any team member to join the discussion for new features or changes to the app.