Very poor My phone was going crazy it was vibrating like crazy. I turned my phone off and It was still vibrating.
v1.01a (Sept 9 2014)
Bugfix: If preferences can't be read, don't vibrate SMS/MMS messages.
v1.01 (Aug 23 2014)
Removed In-App Billing permission. Will not charge anything.
Added initial support for reading MMS messages.
v1.0 (Dec 18 2013)