Apple is getting set to reveal what's next for the software that powers the iPhone, iPad and Apple Watch, and a tool to improve digital wellbeing is being rumoured as the big announcement.

The technology giant is holding its annual Worldwide Developer Conference in California tomorrow.

Reports in the US suggest Apple could introduce a tool to help users better manage their time on their devices as part of efforts to improve digital wellbeing.

Last month Google unveiled a similar tool - soon to launch for its Android operating system - which will enable users to monitor how often they use their phone.