The meeting controls are hidden by default. To access the controls you must tap the screen and the meeting controls will appear at the bottom of the page on an iPhone (at the top of the page on an iPad).
Instead of having to tap the screen every time the meeting controls are needed, you can permanently display the meeting controls so that they are always visible.
Launch the Zoom app and then click on the Settings button at the bottom of the page.
Click on the Meetings link
Scroll down to the “Always Show Meetings Controls” option and click on the switch.
The meeting controls will appear at the bottom of the page on an iPhone, or the top of the page on an iPad.