We have no idea which one of the thousands of unregistered questions was yours. If you'd like to carry on a discussion more easily, please consider registering on this forum.
We get questions about imo with some regularity, but almost never any good answers, since it doesn't seem that popular amongst our members. Try emailing their support:
androidsupport@imo.im. You can always find the developer's email easily by looking at the app's Google Play Store page.