I invite you to check my program "Your Reply", which gives new feature to native message client.
By using the native e-mail client on your phone, the message which you answer and attach the content, is locked, which prevents editing (eg remove a paragraph, signature, etc). Your Reply eliminates the inconvenience! The program gives a possibility to reply and to forward received messages allowing you to edit them beforehand.
The program installs itself in the menu on the message list as additional items "Edit & reply" and "Edit & forward".