Way to go V! I can't imagine 50 anything with kettlebells. 
On the "100 Push-ups" app, just if you're doing them on your own without a trainer, be sure to do the push-ups in good form and balance them with plenty of back and rotator cuff work.
I didn't (despite all my preaching
), and wound up really messing up my rotator cuffs. Nothing permanent, but a lot of pain and expensive massage, and some brief nerve impingement. It's easy to focus on one thing and underemphasize everything else when you're following a program like this one. JME...
Speed comes from what you put behind you. - Judi Ketteler