
Quick answer — FLOW performed 4 anime themes, including "Kaze no Uta" from Tales of Zestiria the X, "Tales of Zestiria X Ending 2 Creditless - Flow - Innosense" from Tales of Zestiria the X Season 2, "BRAVEBLUE" from Eureka Seven AO.
FLOW performed the anime theme songs "Kaze no Uta" (Tales of Zestiria the X), "Tales of Zestiria X Ending 2 Creditless - Flow - Innosense" (Tales of Zestiria the X Season 2), "BRAVEBLUE" (Eureka Seven AO), "Shinsekai" (Shadowverse).
FLOW's first listed anime theme is "Kaze no Uta", the opening of Tales of Zestiria the X.