As of the end of August, TripAdvisor will start phasing out its four-year-old City Guides app and incorporate it into its all-singing, all dancing signature app, which the company hopes will become the ultimate travel guide, says Skift.

All the guides and maps – it has amassed data on some 300 cities around the world – are now available from its main app and can be used offline, allowing travellers to download the information without worrying about data charges.

The move marks the firm's intentions to create a more comprehensive app that is not only informational but also actionable. Using it, travellers can book a hotel, make restaurant reservations, and summon an Uber ride, for example.

But is this the right move for TripAdvisor?

"The challenge for TripAdvisor is whether it will win by being an all-encompassing app or whether it is better to be more focused like Expedia's or HotelTonight's apps. In phasing out its City Guides app, TripAdvisor is putting itself in the comprehensive camp," says Skift's Dennis Schaal.

It's part of a long line of changes to the ever-evolving TripAdvisor app. Several years ago it mainly offered hotel and restaurant information and reviews. Now it also offers the travel guides; tour bookings (from its relatively recently acquired Viator unit); hotel and holiday rental bookings; restaurant reservations through Priceline's OpenTable and TripAdvisor's own The Fork; flight search and airport information; and details about Wi-Fi and roaming at various destinations.

TripAdvisor acquired Viator, a leading destination activity booking site, a year ago, adding the site to its own network of websites.

The Viator tours have been integrated into the TripAdvisor app, but they are also accessible in a Things to Do section that is separate from the Travel Guides. Although TripAdvisor's City Guides app will eventually go, Viator still has a separate app of its own.

In the end, the breadth of content offered by its app will make it hard for other booking apps to keep pace with TripAdvisor's. Even the Expedia app, for example, which offers hotels, flights, cars and activities, doesn't have the comprehensive guide-oriented information of TripAdvisor, and there are no user reviews either.

With its all-in-one app, TripAdvisor has put its eggs in one basket, so to speak – a challenge that the company has no doubt considered extensively. Time will tell whether it will come out on top.