MonkerViewer is a simple program used to navigate preflop ranges. Hold'em and Omaha nGTO ranges can be purchased from the store. A few of these are accessible for free so you can familiarize yourself with the program before spending any money.
Purchased ranges are stored on the cloud and can be accessed from any computer or android phone.
Some poker rooms, notably PokerStars, explicitly prohibit the use of this kind of software in real time. Always check with your poker room before using this software in real time.
Most nGTO ranges contain mixed strategies. You can switch between sampling and mixed view by pressing 'enter'.
You can view your local ranges (exported from MonkerSolver) by creating a folder named "ranges" in the same folder the viewer executable is located, and then placing your exported ranges there.