GP practices in England deliver more than 25m appointments a month - around half of them by GPs and the rest by nurses and other practice staff, according to figures from NHS Digital.
In a speech on technology in the NHS this week, health secretary Matt Hancock said that 'more than a million' GP practice appointments are now booked through apps.
This figure could rise over the coming months as growing numbers of GP practices link up to the NHS app - which is set to be rolled out across England by July.
However, NHS England's board has heard concerns about the laborious login process for patients who sign up to use the app - and some GP services have been unable to link to the software because of compatibility problems.
NHS England said last month that one in three patients in England would have access to the full functionality of the health service app by 31 March.
Under the five-year GP contract that took effect from 1 April in England, practices will be expected to make 25% of appointments bookable online from July 2019.
The BMA's GP committee has said that appointments made available in this way may not all be GP appointments - and that practices would be free to decide whether some or all appointments made available for online booking were with nurses, GPs or other healthcare staff.
Five-year GP contract
Figures from NHS Digital also suggest that practices face a huge task to meet a contract requirement that every practice should offer video consultations by April 2020.
Despite funding promised through the five-year agreement to support the rollout of technology in practices, the latest official data show that currently around 0.5% of GP appointments are delivered via video or online technology.
The new contract also set out other digital requirements including plans for NHS 111 to begin booking appointments directly into GP practices from April 2019, and for all patients to be able to order prescriptions electronically. Mr Hancock said this week that 3m repeat prescriptions a month are now booked in this way.
From April 2020, all patients are also expected to have online access to their full record, including the ability to add their own information and be able to access online correspondence.