Jennifer L. Armentrout books in order
39 books in the catalogue, about 339 hours of reading in all; the shortest takes 4 hours and the longest 15 hours.
2 series and 34 standalone books in the catalogue.
Covenant
5 books 1 Half-Blood length not known
2 
Pure 6.0 h 3 Deity length not known
4 Apollyon length not known
5 Sentinel length not known
Lux
6 books 0.5 Shadows length not known
1 
Obsidian 7.6 h 2 Onyx length not known
3 
Opal 8.7 h 4 Origin 8.2 h 5 Opposition 7.6 h Standalone books
Cursed 5.3 h 
Deity 6.1 h 
Obsidian 6.2 h 
Onyx 7.7 h 
Opal 7.0 h 
Apollyon 6.3 h 
Sentinel 5.5 h 
Stay with Me 8.6 h 
Stone Cold Touch 8.5 h 
Wicked 7.4 h 
Oblivion 6.5 h 
Scorched 4.4 h 
The Problem with Forever 6.3 h 
Torn 6.6 h 
Brave 6.7 h 
If There's No Tomorrow 6.9 h 
Storm and Fury 7.0 h 
A Kingdom of Flesh and Fire 10.5 h 
From Blood and Ash 9.0 h 
Rage and Ruin 10.6 h 
De Sangre y Cenizas 12.3 h 
Flesh and Fire 1 10.4 h 
Grace and Glory 9.2 h 
Shadow in the Ember 11.2 h 
The Crown of Gilded Bones 11.0 h 
A Light in the Flame 12.0 h La Guerra de las Dos Reinas 14.7 h 
The War of Two Queens 10.5 h 
Un Reino de Carne y Fuego 14.7 h Una Corona de Huesos Dorados 4.4 h 
Una Sombra En las Brasas 14.7 h 
Fall of Ruin and Wrath 7.9 h 
Fire and Flesh 3 11.0 h 
Una Luz En la Llama 14.7 h