I've been using mSecure for years. Works well for me and is compatible with multiple platforms. It is backed up to the cloud so I never worry about losing my data. It is $30 one time, not annual.
I went with a 64GB Sandisk Extreme Pro. I had a problem with a Sandisk in my Galaxy S4 a few years ago. Sandisk's customer support and warranty was top notch. I will only purchase Sandisk because of the way they handled it.