No membership chating
Chat Alley has even got you covered with 60-second messages that auto-destruct after 60 second pass. Chat Alley is a perfect app for creating new connections with people that are close by.
Head over to Apple App Store and try out Chat Alley app.
Note that approach (a) changes the sending a chat message / loading a Facebook page from a one-to-one communication into a multicast to all online friends, while approach (b) ensures that users who are neither chatting nor browsing Facebook are nonetheless generating server load.
This one is not a typical messaging app because this one works without internet connection and is also free of any registration hassle.After all, email does work, as well as i Message, Skype, and even Twitter direct messages or Facebook Messenger conversations.Each have their place, and you can get business done with them just as much as with a professional chat app.The naive implementation of sending a notification to all friends whenever a user comes online or goes offline has a worst case cost of O(average friendlist size * peak users * churn rate) messages/second, where churn rate is the frequency with which users come online and go offline, in events/second.
This is wildly inefficient to the point of being untenable, given that the average number of friends per user is measured in the hundreds, and the number of concurrent users during peak site usage is on the order of several millions.Surfacing connected users' idleness greatly enhances the chat user experience but further compounds the problem of keeping presence information up-to-date.