After the long wait (thank you for your patience), the subtasks feature has been released in the latest Android update. Download it here : https://play.google.com/store/apps/details?id=com.producteev.android.alpha22.
Right from the task details screen, you will be able to see the subtasks associated to it. If you click on the subtasks list, you will access the edit screen where you can add, delete (long click), check on/off and change the title (simple click) of a subtask.
This is pretty much following the same flow as the web app and the other native apps. The drag and drop re-ordering will come soon.
**This major feature release requires a complete upgrade of your local producteev database. If you decide to update the app, you will be logged out and on your next login, a complete fresh sync will occur for a few moment. All data -all tasks, workspaces, labels, notes- not synced with the web app will be lost, so make sure you do a full sync before the update.**
Please let us know if you have any comments or questions. The next features will be the social logins (google and facebook sign on) and the Android native push notifications.
Looking forward to your feedback.
The Producteev Android Team.