How to turn off and disable the 'Shake to Undo' feature on your iPhone
Created with accessibility in mind, but not bumpy rides on rural roads, Shake to Undo often results in distracting pop-ups, asking you whether you want to delete all of what you just keyed in, requiring one extra step to clear them out. If you think you can make do without Shake to Undo (pun intended), and the annoying pop-ups, there is an easy way to turn this otherwise noble accessibility feature off.
1. Go to Settings>General>Accessibility;
2. Scroll down to the Shake to Undo feature, which is on by default, and disable it with the slider switch.
That's all, folks, you won't have to deal with pesky pop-ups and text disappearance on rickety country buses anymore.