Hi ital
There isn't any specific legislation about telephone apps. Most apps are not counted as aids because they have not been specifically designed for people with disabilities, and so they are viewed as a choice that claimants make. There are some that have been specifically designed for a range of disabilties. You can argue that you need an alert to take your medication, but they often ignore it unless not taking your medication would be life-threatening.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
