The user agent string is:
Mozilla/5.0 (iPhone; CPU iPhone OS 11_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E302 Instagram 59.0.0.14.81 (iPhone7,2; iOS 11_3_1; es_ES; es-ES; scale=2.00; gamut=normal; 750x1334)

Not sure what browser name actualy is, instagram dont ask to choose a browser app instead.
The parser gets "WebKit" as browser and as engine and 605.1.15 as version.

Tested in last version 0.7.19