Ok guys, I think I got it.
Go to Terminal and perform:
There's a bug in the CFPropertyList gem, a dependency of ipatool, the ultimately responsible for packaging the ipa.
The bug prevents ipatool from listing all the available platforms (This is an extract from IDEDistribution.standard.log):
2015-10-14 15:17:22 +0000 warning: Configuration issue: platform iPhoneOS.platform doesn't have a 'iPhoneOS9.0.sdk' SDK with a SDKSettings.plist; ignoring it. Exception: #<ArgumentError: invalid byte sequence in UTF-8>
/Applications/Xcode.app/Contents/Developer/usr/bin/ipatool:2009:in `block in allKnownPlatforms'
That's why you get the message: "no applicable devices found" (no platforms == no devices)
The bug was introduced in version 2.3.1 and solved in 2.3.2 (I'll include the link to the exact change in the github project but then this reply wil enter "Waiting for review" according to the moderation rules).
So go and check your gems:
This can be your case.