Is there any difference in functionality for iOS and Android devices?

Yes, the range of ZoomOn app features is different for iOS and Android devices. Check the availability of each feature in the overview below.

Live video monitoring
Smart notifications
(may not be available with some HomeKit/ONVIF cameras)

(may not be available with some ONVIF cameras)
Two-way video and sound
Motion detection
(may not be available with some HomeKit/ONVIF cameras)

(may not be available with some ONVIF cameras)
Motion detection recordings
Screenshots and recordings
(only recordings)
Unlimited reach
Zoom-In/Out
(may not be available with some HomeKit/ONVIF cameras)

(may not be available with some ONVIF cameras)
Night mode
(may not be available with some HomeKit/ONVIF cameras)

(may not be available with some ONVIF cameras)
Low battery warning
Multi-home and Multi-owner units
Picture-in-picture
Compatible with other iOS/Android mobile phone
Compatible with HomeKit cameras
Compatible with IP ONVIF cameras
Compatible with other IP cameras