Why are Continuous Integration and Continuous Delivery important in the first place? There are number of answers to this question. One of them is that you need feedback as early as possible. Since you also want to ensure a certain quality level, there may be some friction here. Distributing and testing your app will take a large amount of time, however, you also need to release early and often.
A build server can help you to accomplish this goal, because a build server can, among other things, verify if your code compiles and if your tests still succeed. In addition, it can distribute the app to beta testers or to the App or Play Store. At a specific time, or each time a new feature has been implemented, the build server will be triggered to perform these and other tasks.
Having a smart-branch strategy is required if...