First, I think ManyCam is the best cost / benefit solution for transmitting exclusively via mobile phones (use 3 on mine). But it can improve a lot! My suggestions are:
have simple and advanced interface;
- preview and program windows
- a better v.u. meter (horizontally and large with color division (standard green / yellow / red);
- have information about frame processing time and lost frames as obs has;
in the app have the option of manual focus (the ipwebcam app has), because sometimes we have sweet focus on the mobile;
proper information of the quality of the stream we sent to each service connected;
Finally, the virtual background is important, but IMHO, these options above are more important.