Is GRLevel3 (or GR2Analyst) available for iPhones, iPads, or Android devices?

Short answer… no, and never will be.

Long answer… Mike Gibson is a Windows developer.  He has focused, and indicated that he will continue to focus, on Windows/Intel (WinTel) only development.  Furthermore, GR products rely on libraries and technologies that are only available within Windows.  That said, while some have had success using WINE emulators, it’s often buggy and also not supported.