To make it work you need to install the legacy SimConnect. As explained here: SimShaker for Aviators - Thread from the Dev
Then select Forcefeel as the target device in the SimShaker for Aviators.
This is how I got my HF8 to work. You do not need the (pay ware) sound module.
Yup … as @Mstar78 mentions you need to get this and all will be well.
The NLR app is still very much in its early stages of development, (beta) whereas SimHub and Simshaker For Aviators have been around for quite some time. Once the software has all of the kinks ironed out, more effects and games are added etc. It’s going to be amazing, and completely free. But HF8 owners were never and will never be obligated to use the HFS Software. NLR has done everyone a solid and is continuing to develop an app that has racing and flight games available with free haptic feedback!