Data suggests the UK may have reached already reached almost 100,000 cases - double the current official figure.
The Zoe Covid Study recorded an average of 92,953 daily infections over five days.
Meanwhile, the government announced on Friday that there were 44,702 fresh cases.
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The Zoe data is based on both PCR and lateral flow tests, and says its own records show the number of cases has risen by 14 per cent compared to the 81,823 infections recorded the week before.
According to the data, one in 56 people in the UK currently have coronavirus with symptoms.
Professor Tim Spector, the top scientist on the Zoe Study, said the app's statistics are consistently higher than official figures, due to the fact it includes self-reported lateral flow tests.
It comes after Health Secretary Sajid Javid warned this month Covid Infections could reach 100,00 a day.
Professor Spector said: "The Zoe data shows the UK could hit 100,000 new cases sooner than expected and with no sign of a Plan B or Plan C.
"It's clear the government figures are a big under-estimate, and with the highest rates in Western Europe, there's no room for complacency.
“The government raw figures report on PCR testing of the classical symptoms only, which miss around 40% of cases.
“It’s clear the government figures are a big under-estimate, and with the highest rates in Western Europe, there’s no room for complacency.
“With the UK government delaying any decision while hospitals fill up, it’s time to take matters into our own hands to address the worsening situation.
“Public action has worked in previous waves to reduce rates before lockdowns.”
The Zoe data suggests infections are rising among all age groups. Under 18s have recorded the highest proportion of cases.
According to the app, southwest England has seen a notable spike in infections.
The app's figures are based on reports from around 750,000 contributors as well as the number of people who've tested positive for Covid.
Professor Spector said data showed vaccine protection is becoming less effective and urged those eligible for a booster jab to take it.
He also encouraged the public to wear masks on public transport and in crowded places.
It comes after reports that a ban on household mixing could make a comeback before Christmas which will see family and friends gathering together.
Cabinet Office officials are said to be discussing proposals for a clamp down on socialising as part of a Plan C.
This all depends on whether booster jabs have any effect on virus control by Chistmas.
