Common Lit: Grades 3-5
https://www.commonlit.org/
News ELA: Grades 2-5
https://newsela.com/
ReadWorks: Grades 2-5
https://www.readworks.org/
Generation Genius: Math and Science for Grades K-5
https://www.generationgenius.com/
Zearn: Math Grades 2-5
https://www.zearn.org/
Starfall: Kindergarten
https://www.starfall.com/h/index-kindergarten.php