4 aircraft and 4 cabin layouts, from the A320 to the A321neo. Pick one for its seat map, the best seats and the seats to avoid.
There are seat maps for 4 Frontier Airlines aircraft here: the Airbus A320, the Airbus A320neo, the Airbus A321 and the Airbus A321neo.
The Airbus A321neo, with 240 seats: 240 Main Cabin in its main layout.
The Airbus A321, with 28" to 33" of seat pitch in Economy and seats 18" wide.