The app warns people that they have been in close contact with someone who has tested positive for coronavirus.
People contacted through the app are advised to isolate for up to 10 days, although there is no legal obligation to do so.
Across England and Wales, nearly 700,000 alerts were sent to Covid app users in the latest seven-day period – a record high and 11 per cent more than the previous week.
NHS figures show 3,021 people in Dudley were "pinged" by the Covid app in the week to July 21 – the latest available data. It was an increase from the 2,373 alerts sent the week before.
In Sandwell, 2,624 people were contacted in the same week – an increase from the 1,924 alerts sent the previous week.
A total of 2,343 people in Walsall were contacted to isolate in the week to July 21 – increasing from 1,710 alerts sent out the week before.
The figures show that 2,053 people in Wolverhampton were contacted to isolate – an increase from the 1,526 the previous week.
A total of 1,910 people in Stafford were contacted to isolate in the week to July 21 – an increase from the 1,732 alerts sent out the previous week.
The figures show 1,451 people in Cannock Chase were contacted by the Covid app in the week to July 21 – an increase from the 997 alerts sent out the week before.
And in South Staffordshire, 1,235 people were told to isolate in the same week – an increase of the 802 alerts sent out the previous week.
Communities Secretary Robert Jenrick has urged people to isolate if they are advised to do so, saying there “isn’t very long to go” until August 16, when all fully vaccinated contacts in England who test negative can avoid isolation.
He said: “I appreciate that it is a significant number of people and it can be frustrating, but the app is doing what we asked of it.”
But while isolation is not mandatory for people “pinged” by the Covid app in England, anyone who is contacted and told to self-isolate by the NHS Test and Trace service has a legal obligation to do so.
Across England, more than 295,000 cases were transferred to the contact tracing system between July 15 and 21, with 597,000 people identified as coming into close contact with someone who had tested positive.
The Government said it was expanding its daily contact testing for frontline sectors who are exempt from isolation.
Around 260 sites across the country are available for people working in prisons, waste collection, defence, the food industry, transport, Border Force and police and fire services.
A further 800 are in the process of being set up, with 1,200 more due to be established in the coming days.
Daily negative test results will enable eligible workers who have been alerted by the NHS Covid-19 app or called by NHS Test and Trace as coronavirus contacts to continue working.
Plans to allow fully-vaccinated travellers from the EU and the US to enter the UK without the need to self-isolate for two weeks have also been announced.