Calm, Nispand app (by The Yoga Institute)

Simple movements can be very beneficial and you can also practice sitting in your chair - neck rotations, shoulder rotations, seated cat & cow, side bends, and twisting every hour or two for 3-5 minutes. If possible, sitting in a deep yogic squat (malasana) can be practiced for about a minute every hour- improves posture while improving blood circulation lower body, and digestion.

Balancing pranayamas can really help with calming the mind down- Equal breathing, Bhramari (humming-bee) pranayama, Anulom Vilom (Alternate nostril breathing), and Diaphragmatic breathing are very effective.