Great news, thanks! I will update OKTech later today.
Btw, something else came to mind. The oktech_get_messages function returns only the unread messages, then they are automatically marked as read. Wouldn't it be better to return all messages in my inbox with a read/unread flag or something? I wanted to show the inbox in the app, but right now it is not really possible. The oktech_get_messages_history requires both useridto and useridfrom to be set, so I have no way to get all messages that were sent to me, or that i sent to other people.
If this can't be changed easily don't worry, I will just scrap that feature for now and wait until Moodle's own WS will implement something on those lines.