Samsung Go Prime smartphone.
This is labeled as an AT&T model, but the URL indicates "unlocked" and the item description says "This 4G LTE smartphone is unlocked." Likewise, the phone features mention it's unlocked (see below).
Phone not found in other searches, except the likely similar Core Prime model for T-Mobile that was $90 and included some airtime recently.
However, this one is likely competitive with the ZTE Zmax2 selling for about the same price lately, only for a name brand phone.
Basic features from the web site:
4G LTE smartphone network
Bluetooth v.4.1 technology
Android 5.1.1 (Lollipop) OS
Rear 8 megapixel camera with flash
Front-facing 5 megapixel camera
1.2GHz quad-core processor
Mobile web unlocked smartphone
Questions and comments indicate it has 1 GB of RAM and 8 GB of flash storage
. The user manual (http://www.att.com/support_static..._G530A.pdf
) also indicates microSD support and a removable battery.
The specifics of the processor aren't mentioned, but it's quite likely a Snapdragon 410.