TH3 3.3.0 can be downloaded from our website for free. The actual developer of the software is Overloud Almateq Srl. TH3 lies within Multimedia Tools, more precisely Music Production.
From the developer:
TH3 is a custom guitar effect suite which sets a new reference in amp simulation. It includes 69 guitar amplifiers and 3 bass amplifiers, 35 guitar cabinets and 2 bass cabinets, 75 pedal and rack effects, 18 microphone models, with up to four mics on each cabinet, more than 1000 presets covering all musical style, one entire preset bank dedicated to bass, and more. TH3 is not just an amplifier replacement.
You may want to check out more software, such as enable Encore, Jupiter-8V or Guitar-Online Tools - Tuner, which might be similar to TH3.