The situation, reasons, and explanations behind Samsung’s region-locking of Note 3 devices is still not clear. Fact is that the new phablets come with a region lock; hence, you can’t really use a European model in the US, or vice versa (or another region). However, Samsung claims that once activated with a SIM from the proper region, this lock should go away. Some angry Note 3 owners could testify to the opposite, according to reports.
Trying to set your Note 3 free, this application, while requiring root, will clear a certain blacklist on the phone. As a direct effect, it should allow you, for the moment, to use your Note 3 (unlocked) with any SIM, regardless of region. Of course, Samsung can always update and restore the list via updates. Make sure to hop over to XDA Developers in the source below to read more about this app.