What input method can iphone4s use to send short messages by voice?

At present, the best voice input method is Baidu input method, which takes up much less mobile phone hardware resources than sogou. However, no matter what input method is used in 4s, one thing is true. It is much better if the mobile phone is not upgraded.

The voice input of Baidu input method is: hold down the space bar to speak, it's as simple as that, as shown in the figure, I always reply to you with voice.