This is a free and open source teleprompter program.
Download binary unzip, and launch Open Teleprompter file inside, or download source and compile with unity.
Windows x86 binary: https://github.com/therealmichaelberna/OpenTeleprompter/blob/master/binary-releases/Windows/x86/windows_x86.zip
Linux binary: https://github.com/therealmichaelberna/OpenTeleprompter/blob/master/binary-releases/Linux/Linux.zip
Mac binary: https://github.com/therealmichaelberna/OpenTeleprompter/blob/master/binary-releases/Mac/Mac.app.zip
Copy and paste text and hit play. The text will auto scroll based on the speed in the settings. Can also be scrolled using mouse wheel. Click the mirror button to mirror. Click the gear to change settings.