All Puffin browsers, including Puffin Web Browser, Puffin Web Browser Free, and Puffin Academy use the same format. Here is an example of the user agent of Puffin Web Browser 6.1.4:
Mozilla/5.0 (Linux; Android 7.0; SM-G925T Build/NRD90M; en-us) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Mobile Safari/537.36 Puffin/22.214.171.12405AP
"Puffin/6.1.4IT" is appended at the end of the user agent for Puffin Web Browser. "Puffin" is the keyword. If Puffin is found in the user agent, it is from the Puffin Web Browser.
"Mobile" is the hint showing Puffin is in mobile mode. With or without the hint, as long as the keyword "Puffin" exists, it's from the Puffin Web Browser.
"126.96.36.19905" is the version number, where 6 is the major version and .1.4.16005 is the minor version.
The last two letters with 5 possible combinations represent the OS and the device type: