Your contacts should all be linked to your Google account. To make sure they are, go to https://contacts.google.com and confirm you're not missing anyone. If that list isn't complete, then go into your account settings on your phone and sync your contacts with your google account.
You can buy this simple candy bar type cell phone off of Amazon for $30. It has big buttons, a camera, flashlight, and looks like something an old person would use. Plus it's well under your budget. It should work well on T-Mobile and therefore Mintsim. You should look into what /u/frostcall mentioned too though. I still think your dad would like this phone however.
https://www.amazon.com/dp/B01MDQRZAN/ref=cm_sw_r_cp_apa_hE1KAbB7ZDRKQ
Not Compatible - Huawei Honor 6x and 7x.
my report on the 6x and anther person's confirmation for the 7x is here - https://slickdeals.net/f/11149695-32gb-honor-7x-smartphone-black-or-blue-200-amazon-free-shipping-for-prime?page=38#comments
You need to enable it on your phone (if your phone supports it). Obviously if your phone does not support VoLTE it won't work.
Tmobile just released an app to check.
I have Moto G5 Plus too. The SMS app they use is actually the Android Messages app by Google.
I couldn't get MMS to work right for an hour or two after activating, but then started working fine with the settings Mint Sim says to use. I don't think you should have had to install another SMS app.
In theory, yes. In practice, probably not. I ran the serial number through my Sprint database access (disclosure: I work for /r/ting) and it came up as compatible, but ineligible because it's not in the database.
In theory, once this device is unlocked, if you could find an employee willing to file an ESN Not Loaded ticket in ClickIT, they might add it. I wouldn't hold your breath, though.
Also prohibitive is the software. The phone doesn't report an IMEI and complains about any non-VZW SIM, as well as restricts features like hotspot. If someone could get the above ClickIT ticket approved AND we could get an unlocked bootloader so we could flash a non-VZWpp ROM, it could work. It seems like a lot of work when the unlocked $99 one from Amazon works just fine on Sprint without all the aforementioned hassle.
Get a $4.99 7-day trial sim from Amazon
Mint Mobile Starter Kit | Verify Compatibility with our Talk, Text & Data Plans (3-in-1 GSM SIM Card) https://www.amazon.com/dp/B0786RD524/ref=cm_sw_r_cp_api_cvrwBbD3880D4
I picked mine up last week
I am currently using the VPN Hotspot Shield and have had no issues with connection. I would imagine it either has something to do with the VPN app, the server you're being connected to by the VPN, or your account. I don't think it has anything to do with MintSim's service. If you haven't tried contacting their customer service I would do so to see if they have a resolution available for you.
Well, I imagine that few people are foolish enough to actually have a direct AT&T plan in 2017. $50 a gig? How 'bout nah.
If you're serious about it, I know that a couple command lines in Linux, and a VPN, send data over the network in such a way, that the provider is unable to determine what type of device is being used.
But let's hope that Mint SIM doesn't take hardlines against tethering.
Back in my PAYG T-Mo days of yore, the tethering function on my Nexus 4 only worked on HTTPS sites that T-mobile's "buy tethering" page couldn't hijack. The HTTPS Everywhere add-on for Firefox helped a lot, and only a couple of HTTP-only sites like Amazon were left off limits. I wonder if this will be the same, 5+ years later.
If you're super nerdy, I've also read that command lines on the actual phone itself, coupled with a basic VPN like Speedify, will also disguise the data packets. Very sadly, phones can't tether a VPN connection out of the gate by default.