Neither 'app' or 'bitbar_app' is mandatory in Bitbar Testing Cloud. In fact 'app' capability should never be set by customer in Client Side Execution.
Without setting 'bitbar_app' Appium is still able to start all apps installed already on device like i.e. 'Chrome' 'Play store' etc. Here You can find python working sample for android chrome test https://github.com/bitbar/test-samples/blob/master/samples/testing-frameworks/appium/client-side/pyt...
