Hi,
The newer HM-10 with serial interface works well.
Info HERE
Info and some example code and Smartphone examples HERE
Be aware that there are two flavors of HM-10 out there. One has no level-shifting (or resistive shifting only) and usually costs about $6 and the other has an onboard level-shifting chip and costs about $12...
Examples from my shop: HERE and HERE
DISCLAIMER: Mentioned stuff from my own shop...