Here is what I'll suggest you:
1) create a Java program to call DMS provided Consolidator APIs to create mobile user ids in mobile server's repository per provided user names/passwords, the Java program loads configuration which specifies a bunch of user names/passwords, mobile server URL and mobile server repository JDBC URL, thus, the it is once created and can be used for ever against different mobile server instances. This Java program will run to create bunch of mobile user ids in advance, and it can run on any platforms (Windows, Linux) only if Oracle Java SDK is supported.
2) use a way to distribute the mobile user id/password/mobile server url to your field workers, eg. via email.
3) on the device, the field worker downloads your business application from App Store, which will do the business, manage the embedded client databases and launch synchronization.
PS: DMS supports one way Sync, please refer to this post: https://community.oracle.com/thread/2617859.
Oracle Database Mobile Server Development
winnie.hu at oracle dot com