This week's book giveaways are in the Scala and Android forums. We're giving away four copies each of Machine Learning Systems: Designs that scale and Xamarin in Action: Creating native cross-platform mobile apps and have the authors on-line! See this thread and this one for details.
Signing is a way to demonstrate that the file comes from a reliable source and that no one has tampered with it.
This is especially important for MIDlets, since an application can be uploaded from a number of insecure channels, including a rogue Bluetooth connection ("Bluejacking") and may have come from a server whose integrity cannot be assured. Or through channels which could inject a trojan.
An IDE is no substitute for an Intelligent Developer.
What's that smell? I think this tiny ad may have stepped in something.