Keyboard App Builder allows you to take an existing Keyman keyboard for Android, and bundle it into a simple app with a point-and-click style wizard. It is currently in Beta at https://software.sil.org/keyboardappbuilder/ and the developers are looking for feedback.
Please note: this project is not developed by the Keyman team – the support forum for Keyboard App Builder is at https://community.software.sil.org/c/kab