Re: Horsecrap - MyffyW
1st party = Nexus or Google Pixel
2nd party = Samsung, LG, Huawei, etc devices on an OTA upgrade path from the OEM
3rd party = a customised version of 2 sold to you by a carrier, with special uninstallable carrier apps skins bootup logos etc.
The patches trickle down from 1 (Google) to 2 (OEMs) to 3 (Carriers), with a large drop-off rate along the way.