As has always been, apps must be written specifically for every specific device model number as well as major OS level. The Q10 and Z10s are different device model numbers...hence, the developer must write for both. Not all choose to.
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.