Please try to restart your device.
We should mention that iRig HD or other devices that use the lightning adapter provide a better, more reliable experience than iRig and iRig 2 that use the headphone jack (which is not as good and results in feedback for some people).
It is possible, that you can hear some noise while the battery charging. We highly recommend you not to use Tonebridge app while charging or just try to use another socket.
You can reduce or eliminate these sounds by using the “Noise gate” tool. This can be found in the "Additional settings" at the bottom left corner and will reduce or eliminate unwanted noises and feedback. Just increase the value of "Noise gate" until you are happy with the sound, but we do not recommend you to set this to maximum since this may adversely affect the sound of the guitar.
In case of strong feedback, the signal's settings will be automatically adjusted so that feedback gets reduced.