Due to the need of reliable integration of all sub-systems like gyro, accelerometer, ambient light sensor, and other critical components, at this time there is no other system that is reliable to do the job except iPhone 4 / 4s with the Apple iOS.
To perfectly mount iPhone 4/4s in the bracket with +/- 0.003" every time, we assume that the only thing on the iPhone 4/4s that is made extremely precise is the stainless frame which is +/- 0.001". So if we add a rain/vibration cover, we are not sure about the accuracy and there are many different sizes and shapes of waterproof cases on the market which makes it virtually impossible to make a bracket which will fit all the cases with high accuracy.
It is always a good idea to put your iPhone in Airplane mode when using iBowSight. When the phone rings, the dominant App will be the phone App, until one puts it in the background and makes the iBowSight the foremost App. Otherwise, the iBowSight App will be sent to the back and cannot be seen. It will be devastating when one is pulling back and aiming at a deer and suddenly the phone rings. Regarding text messages, they will only roll on the very top of the screen which will have no effect to the operation of iBowSight when one is receiving a text, even when it is not in Airplane mode. Below shows what happens when iBowSight is the Foremost App and a text message is received.