THIS DOES NOT WORK ON ANDROID KITKAT 4.4 AND ABOVE.
Only the default SMS app can delete message.
Google have already copied most of the functionality I worked hard to put into this app anyway. Look in the sms app settings.

Speeds up unresponsive messaging applications.
Can delete messages over a certain age, keep a set number of recent or trim threads to a set size.
Auto cleanup deletes a SINGLE sms matching criteria when a NEW sms arrives. (Auto cleanup is not compatible with all devices unfortunately)

Click wrench to configure.

Notes:
Does not delete messages stored in the "deleted" folder on some devices.
Locked SMS messages are deleted.
MMS messages are not deleted (only SMS).