The MailOnline app is named after the Mail and The Mail on Sunday website, and offers breaking news, show business gossip, pictures and sports stories. It hit the iTunes store last Friday.
After the initial free period users are required to pay for the app, which is priced at £4.99 for six months and £8.99 for one year.
Thomson Local is another new chart entry at number four, while the Facebook app retains its top spot for another week.
The Thomson Local app enables iPhone users to access the company’s database of over 1.8 million UK business listings.
The free app also allows users to read reviews from other customers and leave their own ratings and reviews in real-time.
The chart is powered by analytics app developed by with non-commercial branded apps removed.