Must be Able to be Activated on Ting - Verizon
    Ting.com is an MVNO for Verizon.

    How to Check
        Go To:   ting.com --> "Check your phone",   and enter your phone's IMEI
    How to Find Your Phone's IMEI
        see: Swappa FAQ

Must have an Unlocked Bootloader

    How to Check for an Unlocked Bootloader

        Turn on Developer Mode
            Settings -> [System] -->About phone --> tap on "Build number" 7 times
        How to tell if you are already a Developer
            a message will tell you on the first tap
        How to tell if your Bootloader is unlocked
            Settings --> [System] --> [Advanced] --> Developer options --> OEM unlocking,
                and slide the button to the right

       If "OEM unlocking" is absent or grayed out you do NOT have an unlocked bootloader.

       [extra step] - some versions of Android have extra steps

Please tell me your Phone's Codename
    Every cellphone model and variant has a unique codename.
    I am particularly interested in a:
        Pixel XL               codename 'marlin'
        Pixel XL2             codename 'taimen'
        LG G3                 codename 'd855'
        LG G5                 codename 'd850'
        Moto G7             codename 'river'
        Moto G7 Plus     codename 'lake'
        Samsung Galaxy S7             codename 'herolte'
        Samsung Galaxy S7 Edge    codename 'hero2lte'
        Samsung Galaxy S8             codename 'dreamlte'
        Samsung Galaxy S9             codename 'starlte'
        Samsung Galaxy S9+           codename 'star2lte'

    How to Find the Codename
        On most Android phones.
        Power Off
        Press and hold the Volume Down button.
        Press and hold the Power On button
        The phone will boot to "Fastboot Mode", with the Android robot lying on its back.
        The line: "Product/Variant:   <codename>...", has the codename.