Boomerang and Oukitel Devices: Exempt Boomerang from Battery Optimization

Background

Oukitel, by default, uses aggressive battery optimization which "kills" background processes, so we have to exempt Boomerang from this aggressive battery optimization.  Thankfully, Oukitel does provide a method to have the permissions "stick." 

Solutions

From the child's device, go to Settings, Apps and Notifications, Battery Optimizer, there is a heading here that says not optimized with a down arrow. Click the down arrow to reveal the all apps option. Select that.  Find Boomerang.  Select don't optimize.