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For the most part, I use Spire like crazy. I spend a lot of time in the car and it makes texting while driving slightly more legal. That aside, I'd say that TetherMe is a close second.
 
I love BiteSMS's features but for some reason it was buggy for me and it annoyed me too much to look past. For instance, when I respring or clear the bitesms app from the multitasking bar, it would do this refresh/scroll thing that looked glitchy. When I do the same thing to the messages app it just sits there and updates/refreshes without glitching or twitching. Another thing, when I would go into the bitesms app there would be this ghosting effect with the text. I actually had a post a little while back explaining the problem and I was actually able to take a screenshot of it as it happened. Anyways, it didn't run near as smoothly as the stock messages app and that's what irked me the most. I don't know if anyone else noticed those things but I did.
 
IntelliScreenX or LockInfo.... I can't live with an empty lockscreen, I really need to see my upcoming appointments.
 
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