I dislike services and apps that require that you create an account before you can try them out or use part of its functionality that you are interested in.
It is understandable that companies want user registrations as it may bind users to the service, provides them with information about the user and may look good on paper when investors demand growth or want to invest in the company.
I review lots of apps and services of which only some make it here on this site and one of the reasons for not reviewing a service is if it forces me to register an account before I can even find out what it is about.
Foursquare made a change recently that opens up the application on Android and iOS for unregistered users.
You had to create an account using Facebook or email previously before you could start using it which is now no longer the case.
When you run it for the first time after installation on Android for example, you get the sign up options but also a new button that you can tap on to skip the sign up at this point in time.
It is interesting to note that you can still personalize and customize Foursquare without account. The app displays a taste cloud to you which you can select to add these tastes to your profile. It is possible to skip that step if you are not interested in sharing information about your favorite food on the page but if you do, you may get recommendations based on that.
The main interface of the app opens up afterwards which you can use to find places of interest nearby. The app uses location services for that and displays a couple of topics of interest, e.g. lunch, dinner or shopping that you can explore.
The exploration works without accounts and if you are good with that, there is no need to register an account.
Foursquare displays an option to register an account though. This is mostly important to users who would like to write reviews, rate places or interact with the data in other ways.
I like Foursquare especially when I'm in a location for the first time as it provides me with a selection of well-rated places. I never really liked the account requirement for that considering that I'm only interested in recommendations and have no interest whatsoever to review places.
Opening the app up this way will likely have a positive effect on the number of users who download it and give it a try.