ProPresenter worship and presentation software can be used in conjunction with Ecamm Live to add titles, text and slides to your live broadcast. Details on sending the output of ProPresenter to Ecamm Live can be found here.
Before lyrics and other text from ProPresenter can be presented over Ecamm Live camera video, you'll need to ensure that the slides have a transparent background.
IMPORTANT: ProPresenter 6 and ProPresenter 7 are completely different, and have different set-up steps.
Transparent Background in ProPresenter 6
To do this in ProPresenter 6, click the document icon in the Editor sidebar, and then ensure that Background is turned off or set to clear.
Then, click the slide icon, and ensure that each slide's background is turned off.
Transparent Background in ProPresenter 7
To do this in ProPresenter 7, go to Edit mode. Click the Presentation tab in the Edit mode sidebar, and ensure that the Background checkbox is turned off.
Then, click the Slide tab, and ensure that each slide's Background checkbox is turned off.
Check Alpha Key Settings
If slides are still not showing up transparent in Ecamm Live after ensuring that slides are transparent, and you are using NDI, check the NDI alpha key settings as described here.
And finally, if you are using Syphon, ensure that the Screen Color checkbox is not checked in the top corner of the Screen Configuration window.