We would love Mailtrack to work in your Gmail app for iOS devices, but for the moment Mailtrack Add-on is only compatible for Android phones. The truth is that it doesn't depend on us. Add-ons compatibility for iOS depend on both Google and Apple collaboration.
Mailtrack Add-on is ready and will work automatically in iOS when those compatibility issues are fixed, no work needed in Mailtrack side. We have been told that Google and Apple are working on Add-ons for iOS, but the release date is still unknown.
We will announce it to all Mailtrack users as soon as we know about it.