The current iOS Lumos doesn't support phone numbers outside of US.
I will address this problem in the next release (the version number will be 1.1) but it would take for a while (at least more than a week) to pass strict Apple's review.
But while waiting, the people outside of US can do some work around.
1, You can download the source code from GitHub and build by yourself. Please read http://dev.tinkermode.com/docs/lumos.html The latest source code already is fixed. So you just need Xcode.
2, We also provide Lumos on Android. If you have Android phone, please try it. Android version should work with +country code for i18n code.
3, You can use App simulator
If you have any further questions, feel free to ask us.