Facebook applications are an innovation aimed to help their owners to make the most of one of the largest social networks. But like any other popular novelty, this Facebook option raises a lot of questions too.  
 
In this article you’ll find tips and recommendations which can be helpful when planning, designing, and developing Facebook applications.
 
Facebook Development Platform - Innovations and... Volatility
 
Facebook is growing fast now. The number of Facebook users escalates in thousands and millions. It means that Facebook apps owners get increasingly more potential users every single day. 
 
But this coin has a reverse side too: due to Facebook rapid evolution tools for the application development - Facebook API (Application Programming Interface), etc - are changed quite often as well. Owners, designers, and developers should keep track of such new features because they can affect appearance, functionality, and operability of existing applications. 
 
1). So, before starting planning a Facebook application make sure you have read Facebook Privacy Policy (http://www.facebook.com/privacy/explanation.php?ref=pf) and Facebook Developer Principles and Policies (http://developers.facebook.com/policy/). These documents contain lists of limitations that should be taken into account while designing and developing your Facebook application. If your application doesn’t correspond to them, the Facebook team may not approve it for using on Facebook.
 
2). Read Facebook Developers Roadmap (http://wiki.developers.facebook.com/index.php/Developer_Roadmap) to be aware of the upcoming changes and to forecast respective modifications of your application in advance. 
 
Frankly, documents mentioned above are not bedside literature. If you outsource their reading and learning to programmers, just remember that there are some constraints and internal rules on Facebook which can change with time, and your FB application should follow them.
 
Successful Facebook Applications Start from Successful Design
 
Design is extremely important for Facebook application success. In order to provide good look and feel of your FB app take into account the following points. 
 
1). Design should be an integral part of a general application concept and convey ideas and feelings behind it.
 
2). Design should be user-friendly, intuitive, and of playing style to some extent, because Facebook apps are entertaining by their nature. That extent depends on your application niche.
 
3). Design should be social-networking and viral - and give a user a supporting environment to socialize with other users. Does your design encourage people to communicate and make invitations? Does your design help people to express themselves and show them in a favorable light among their friends? Will users say each other "Wow, just take a look at that app!" ?
 
4). Design may impose certain restrictions on a Facebook application and, therefore, cause problems when programming the app and afterwards when adding new functional features. As a result, a FB application design should be flexible and simple enough to be able to reflect that constant Facebook growth we’ve discussed above. 
 
5). Also remember that potential users are spoiled by numerous already existing applications competing for their attention. So, analyze your competition to understand what and why is popular and how it can be overcome.
 
Facebook Apps vs. Facebook Connect - What Is the Difference From a Development Viewpoint?
 
Basic-level components of Facebook Connect are scripts which help to realize such options as sharing a piece of content or a link from your website onto Facebook, driving fans to your Facebook Page, etc. Such scripts are ready-to-use and easy-to-install onto a website.
 
Unlike it Facebook apps are software applications which are developed from scratch using Facebook Development Platform (Facebook API), as well as PHP, AJAX, MySQL, and other programming languages, libraries, and so forth. No wonder Facebook applications development and integration require designers, programmers, testers to be involved, and it is very similar to the creation of any other piece of conventional software. This is also true for Advanced Facebook Connect options and their tuning.
 
Facebook applications shouldn’t be confused with ordinary websites too. Usually FB apps are complex web-based systems with a lot of back-end (server-side) modules which, actually, provide app functionality and make the application attractive for users. 
 
Facebook applications and Facebook Connect are all the rage now. What your FB app will be - just an attempt to follow the fashion or an effective tool to make the most of Facebook - depends on many factors. The deeper you learn and understand them, the better your result will be.