Unfortunately iMindMap 6 & 7 are not supported on Linux operating systems. Only iMindMap 5 is.
iMindMap 7 & 6 are only supported on Windows XP 32 Bit, Windows 7/Vista 32Bit and 64Bit and Mac OS X 10.5 or higher.
You can also access iMindMap on the iPad, iPhone and Android mobile devices through the free app that can be downloaded through iTunes or Google Play.
You can also access the iMindMap Cloud Online editor for free through the following web page: http://app.imindmap.com