Streamlining mobile app deployment with Jenkins and Fastlane in the case of Catrobat’s Pocket Code

This paper describes how we improved speed and reliability for deployment in the case of Catrobat's Pocket Code, a mobile open source project with over 500 contributors and 28k active installs, by moving to continuous deployment. Pocket Code is a mobile app supporting multiple languages including right to left languages such as Arabic, Farsi, and Urdu. This leads to additional repetitive tasks during deployment. The main challenge of a transition to continuous deployment is acceptance tests done by product owners, which in our case, take place as a step during deployment and lead to overall deployment prolongation. Another challenge is the translated application descriptions for the app store for all supported languages which lead to a huge amount of repetitive tasks. Creating screenshots for these languages is tedious and error-prone and further, prolong the deployment. This paper describes how we used Fastlane, a mobile app release framework, in conjunction with Jenkins, a continuous integration server, to improve app deployment in terms of speed and reliability. Deployment steps which are not automatable are moved out of the actual process which is supported by the staged deployment approach of Google Play. The presented approach was also successfully tested with Pocket Paint, another Catrobat app on Google Play, which shows it can be easily transferred to fit other apps supporting multiple languages.