Apple's Voice Control feature is decent, but aside from making calls and playing music, there's not much else you can do. But now, this new jailbreak tweak can equip you with system-wide command over Voice Control, comparable to Android.
Made by iPhone developer chpwn, this workaround expands Voice Control and lets you create custom voice commands for your iOS device. VoiceActivator sits in Settings, where you access a list of assigned keywords that you speak aloud to your phone, and their corresponding actions. Say "hello," and your phone can speak back with a custom message. Tell your phone "Google," and it can zip to your browser and load Google's homepage. You can assign words to trigger certain iOS actions too, like taking a screenshot of your current screen.