I don't think it's too much the specific phone you're using but perhaps the version of android. If you're on an sIII then you have at least 4.0 which is fairly aggressive with killing processes if they don't tell the os not to. Sure screebl sorely needs an update, mine is sometimes not quite reliable but I can't live without it. I too wish they would update it or at least open source the code on a git repo or something....
I’m using it on a Galaxy Note II with no issues.
Scott Weiner
CEO
DBA Cases, Inc.
While they are very slight, and surely not enough to quit using it, I'm pretty sure if you ran logcat you would see some crashes if you're on 4.0+android
Actually there are problems when entering stuff when I inside a browser. It works perfect on email and SMS.