I have this one, Coghlan's Time/Temp Digital Dangler. It isn't perfect but it works, I will replace it when I find a better one.
What I like, it has time, alarm and temp. Records current temp and min max, till reset.
What I don't like, it's not back lit so you need a flashlight to read it, it's not water resistant, mine was in med rain for 30 mins and blanked out on me. I put it in a bag of rice for 24 hrs and its working again. Like I said, I plan to replace it.