Chris Griffith discusses the challenges and solutions for developers who relied on PhoneGap Build for their Android app signing keys, particularly given that these keys cannot be regenerated if lost. With PhoneGap Build shutting down, Griffith outlines a step-by-step migration process to create new signing keys and transition apps to a new version, including generating a new key, cloning the existing app, and submitting it to the Google Play Store. The process may involve creating a data transfer plan if local data needs to be migrated. Griffith also suggests using Ionic Appflow for cloud-based app development and deployment as a modern alternative to PhoneGap Build, highlighting its capabilities for continuous integration and delivery across mobile platforms. Throughout the post, he provides guidance on safeguarding the new keys and ensuring a smooth migration for app users.