I used an old SIM and went through activation for the free plan then end up with "call customer service" who said the SIM expired (got it 3 yr ago on their 99 cent sim deal) and have to buy a new one for $20. Gonna wit for better pricing...
With iPad, can you get a free T-Mo SIM at Apple Store, like with Sprint LTE SIMs?
I don't remember. I got in when the sim was 99 cents, like you, but then I activated it right away. Recently, I bought a $5.00 SIM because someone gave me their T-Mo mifi device and I'm thinking of trying it out.
You can definitley still get it, just signed up on an iPad pro last week in fact. We've had in on 4 iPads now, it's a choice with an Apple SIM. But even better, a newer iPad with Apple SIM often gets a $10 offer for 5 months, 5GB TMobile, which I gladly took. The 5GB is total for 5 months, use as fast or slow as you wish. That stacks with the 200MB offer though, so, you actully get 6MB over 5 months for total $10.