Ever since I discovered I could record colours and tones on a portable back-lit screen, my ipad has become another tool for artistic endeavours.
The illuminated screen means that I can work in a place where there is no ambient light, and being such little kit, makes possible working in places where watercolour, oils or pastels would be almost impossible; as for example in the seat of a car or aeroplane.
However when working from life I find there are limitations on the control I can achieve with the drawing, so I prefer to make loose notes of colour and tone.
Sometimes, in order not to loose the freshness of a painting or sculpture, I can use the ipad to rework on an imported image of the artwork to make corrections or to experiment; that way I can solve problems and be sure of the changes I want to make.
The ipad is a handy teaching tool too.