I have an iOS and Andorid phone. I use my Nike training club app. I've found some great interval work outs (example: http://www.self.com/plan/self-x-tone-it-up-challenge/cardio-1).
I googled interval timer app but there are so many. Do any of you have a recommendation for a great free one? Preferably free, if not it could be a paid app.
Best Answer