PERFECT! $4 MicroSD card MicroB OTG adapter ! www.monoprice.com/Product?p_id=11194
I have a 32GB microSD card and my CyanogenMod 10.2.1 reads it no problems with ES File Manager. 15MB/s performance
Double bonus, if your smart, you use a microSD+Adapter for your Point and Shoot digital camera... so you can easily pop the microSD and attach to phone.
My internal microSD card is formatted ext4, and cyanogenmod picked up this external card when I formatted it as ext4, but...