PDANET+

No, it isn't.

Same function different cost.

The three wifi hotspot apps all work the same but: Verizons hotspot is, for lack of a better word, legal and Verizon supported.
The other two are aftermarket hotspot apps that will also work and work well but is not supported, endorsed (probably a better word) by Verizon.
Remember, Verizon likes to be in charge of the service(s) is provides.

I use PDANET+ whenever I am not in range of a open wifi, and have a Verizon signal. It works well, especially if you're on a 4g Verizon net. I use it with a Samsung Tab 2 10.1. You don't have to pay Verizon a dime, don't have to register it with V and pay them the $30 for that, and don't have to let them know you do that. Its all legal, they got sued and are now prohibited from blocking access or requiring V Hotspot. Except for not getting that one-time $30 activation charge, why should they care? Its all coming off the same data package.

The only bug I've seen so far is that PDANET+ turns off your phone's wifi, and does not turn it back on when PDANET+ is closed. You have to do that manually after you're done with PDANET+, and expect to use your phone's wifi feature.

Foxfi is a one time $8.00 fee using your already paid for data for a hotspot. Verizon is an additiona $20. every month for a hotspot

Unless you root your phone and turn off the hidden monitoring apps in the phone, it doesn't matter what application you use for tethering. Your provider will see it and charge you extra (for what IMO should be free).

I use a rooted Galaxy Note, and froze all the AT&T monitoring services. Free tethering, although I don't have unlimited data.

I pay for tethering, so I don't bother with what item I use. I also use a custom ROM (makes a significant impact on battery life with Android.)

Even with that, I still use PDANet/FoxFi (both apps are merged now), as it has the best interface, especially with connecting a tablet.