There was a download of NRP-Toolkit 3.50 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available.
We cannot guarantee that the program is safe to download as it will be downloaded from the developer's website. Before launching the program, check it with any free antivirus software. The most popular versions among NRP-Toolkit users are 3.5 and 2.1. The program is categorized as Education Tools. This free software is a product of Rohde&Schwarz.
From the developer:
The power meter software application R&S NRP represents power measurement for the most relevant frequency bands and power classes. By communicating with R&S NRP-Zxx Power Sensors the program covers a wide range of applications. Besides the basic continuous average measurement function, R&S NRP also includes the measurement modes timeslot, burst and scope measurement.
You may want to check out more software, such as Panel, gitoolbox or SoftArtisans OfficeWriter, which might be similar to NRP-Toolkit.