Mobile applications, and especially mobile games, are frequently used in short bursts. These bursts could be due to short attention span, short task, incoming call or message, the train arriving, or any number of other things. Thus the user will frequently exit the application, either intentionally or unintentionally.
Once the user exits the application, if you don't want her to use the application again, do some of the following:
- Have an unnecessarily large application footprint. That way, the application will take a long time to load, so the cost of restarting the app is high.
- Phone home with every launch. This technique lengthens the time until the user can start using the application again, prohibits her from using it without coverage, and can run up her data charges. You wouldn't want to set a time stamp for end of license and only phone home when the license has expired - no, that would let people back into the application too quickly!
- Don't save user data. If the user has to re-enter data, she is less likely to use the application again. If she gets interrupted in the middle of searching for an airplane ticket, by all means erase all the search parameters.
- If you have to save user data, save it for a long time. Our fearless user will definitely want to search for a ticket for August 12 the next time she uses the application - on August 15.
- Be oblivious about user context. You know that your user is on that trip to Tokyo ... offer her information about events happening in New York! Especially if she lives in London.
- Destroy user state. A more advanced version of "don't save user data", this will require users to start at the home page or main screen every time she starts the application. You wouldn't want to return her to the news item or video clip she was viewing two hours ago - make her find it again!
- Force a single user interface onto all devices. Especially fun is requiring touch screen users to use virtual hardware buttons, but using one of the softkeys as "Back" on a device that has its own Back button is particularly popular. Couple this with making the hardware back button inert! After all, the user knows how to use her own device's user interface paradigm: you wouldn't want to support that.
- Use a tiny font and subtle colors. This technique increases users' eye strain.
- Don't remember the user. Requiring the user to type a user name and password each time adds to the experience. Advanced: require mixed case, numbers, and symbols in your passwords.
- Expire passwords and sessions after a couple minutes. Those of you in the financial sector know all about this one, but some of the rest of you haven't tried this trick yet. Because somebody might walk away from a computer and expose secure data to prying eyes, keep the session timeout for a mobile device very short, because people walk away from their phones all the time, letting strangers use their connection and services.
There are more methods. Can you give me your favorite? I'll post a new collection in a few days.
Note that when you comment, an error will appear. Your comment has indeed been received and will be unscreened soon. We are working on this.