SwitchService is a new tweak al Cydia which was created especially for those who send messages using their own iPhones, allowing the quick choice of the way in which a message is sent, i.e. if it is sent as an SMS or as an iMessage.
As you can see from the image below, by holding down the Send button in the Messages application interface, you will see the option to choose whether the message you want to send will be sent as SMS or iMessage from the application.
Compatible with iOS 9. SwitchService lets you hold down the send button in the Messages app to switch between sending your message as an iMessage or SMS. Configure options from Settings.
SwitchService is available for download from the BigBoss repo of Cydia following this link.
