There is only one file type that uses the .TNSP extension:
TI-Nspire PublishView Document
Calculator program created by TI-Nspire, a desktop application used for creating programs for TI-Nspire graphing calculators; saves a program published in a format that can be run in a Web browser by the TI-Nspire Document Player, which is available at the Texas Instruments website.
|Texas Instruments TI-Nspire Software||Paid|
Updated: February 7, 2017