I see exactly what you're saying. not sure that there is one out there - but I certainly have not seen it.
As well, I wish that they would work in a search function in case you wanted to locate an email/txt that was sent to you somehow. Being that txts have no subject, maybe a search from the sender?
Having to go thru a gang of txts to find one thing can be a pretty long process... Makes me feel like CSI though...
H!