Which iPad mini app works best for phone calls.

I read that I can use my iPad Mini (mid-2011) for making phone calls. I want to get a mobile hotspot

as well. Can someone advise me of the one that is best and simple? I can get a contract if I have to

but I would prefer not to. In our area, Santa Barbara, Verizon is the fastest. Do I need LTE to surf

the web?

Thanks.

tenacity