What are examples of apps or brands that failed because of their lack of a community?

The most recent example of an app that failed learned from its mistake and then succeeded  was Wander. Initially it was an app to learn English. But  the owner found that the members were more interested to link with people with other countries and learning English was a2ndary requirement as a common medium of communication was needed. After the changes were made the app succeeded.  Many of us are comfortable with computers and like to travel but may not have the resource or the time. Wander provided the avenue of virtual travel and hence succeeded in the2nd try as it heeded to the advice of the audience. Apart from being a professional website Bayt.com also facilitates interaction of people across continents which has made the website very popular.