Jaybird Freedom Bluetooth Earbuds
I've personally had these earbuds for over 2 years and they are fantastic. The pairing is a little bit difficult but if you actually read the manual then it is no problem. I have paired these with both Apple and Samsung phones without issue. They come with several different earbud pieces to ensure a proper fit.
They easily charge with a USB micro adapter. There is a port covered with a gray rubber material to make sure dust and debris doesn't get inside. Once charged they easily last several hours, if not longer. You can control the volume from the headphones themselves or from the device (iPhone, etc.) you are using.
Overall: I highly recommend these as I personally have used them for over 2 years and have had no issues whatsoever. These are a great option under $100.
Pros: long charging life, easy pairing, great sound.
Cons: not fully in-ear buds as they are adjoined with a strap. Strap can be a bit cumbersome if you are sweating.