Switching from iOS to Android. Must have Apps/Widgets?

Hey guys, first post. I'm switching from an iPhone to the HTC One once it comes out in the US. I've always had an iphone, but I love the fact that you can easily tinker and make android exactly how you want it. I'm also extremely impressed with the HTC One so I'm making the switch.

So, what apps and widgets do you guys have and recommend? Also, for people that have other apple products (MBP and iPad), how do those work with having an android device?

Thanks!