Yes! You can use ModelTalker as one of your device voices. You can find out more about building a ModelTalker voice here: https://www.modeltalker.org/faq/
The app also supports message banking, where a user saves a full recorded message into the phrases section of the app, to be played back later.
Please note that although we support ModelTalker and love the work they do, we are not directly involved. We are able to help with relatively simple queries, but for more in-depth help, it may be easier to get in touch with ModelTalker directly.