As of June 7, select Fitbit fitness trackers are on sale at Amazon and Walmart for up to 25% off: OUR TOP PICK: Fitbit Versa 3 — save $30 BEST VALUE: Fitbit Versa 2 — save $30 BEST FOR KIDS: Fitbit Ace 3 — save $20 Mustering up the energy to get outside and get more…