Weetobix

I've been using it too - it's nothing special, but having the app on your phone helps to keep a record and makes me more likely to finish the task. So results do happen

Never too late to start! My best bit of advice is to practice a lot and to make sure to get technique right before applying power. I'm in my mid thirties and really have felt the benefit recently (especially in terms of joint health) of making sure I practice my kick technique