Services like ring plus rely on wifi-powered calls to keep the rates low (so they say) so I dont think wifi calling is that incorrect of a term...
Ah, noted. I would still say that calling RingPlus a "WiFi-calling service" is still a tad misleading due to it being an MVNO competing with other MVNOs. Yeah, it's not entirely incorrect, but it is confusing.
Anyway, US Mobile's rates are very good like you said and that would probably be enough for me regardless
It does kinda suck that there isn't an MVNO with rates as stupidly-low as RingPlus though.
In my digging, I've found US Mobile offers the second-cheapest monthly plan. Unfortunately, your standard package expires after each billing cycle, so if you have 70min and 255MB data by the time your cycle is up, then all of that is wiped out and you start anew from 100min and 500MB data, for example. However,
any top-ups you purchase always rollover to the next billing cycle. US Mobile also has the lowest per-line service charge I've ever seen ($2, which is only beat by RingPlus's charge of $free.99). Thankfully, US Mobile is on T-Mobile's network, which the Pyra is compatible with.
There's also Ting, which now offers GSM service (also uses T-Mobile's network, so works with Pyra). With Ting, you're not buying a monthly plan; you're paying as you use. You could go from $41/month (up to 100min, up to 100 texts, up to 2.5GB data) to the minimum $6/month (no usage, paying only the service charge). Basically, if you have the aforementioned amounts set as hard-caps and you only use WiFi texting/calling/data, then you only pay $6 since you didn't use anything, which beats US Mobile's monthly plan.
However, I'd settle for US Mobile to keep my bill consistent.