My Products have been thoroughly tested on multiple devices. Occasionally, new operating systems or devices will result in an unstable application. If you are experiencing problems, please check the FAQ as they answer many of the registration and activation issues people experience. If you are still unable to resolve the problem, please contact me at: support@em-innovations.com I will respond in a timely fashion and assist you. Thank you for your patronage, and I hope you enjoy my apps. I have found them to be very handy while working in the ED. -dan