Lawyer fees will often run over $15,000 to do everything from determining the patentability of your app, searching to if it all or part is already patented, filing the draft, and actually applying for a patent. However, the patent itself only gives you the right to sue.
The litigation process for infringement on intellectual property is also quite expensive. For any entrepreneur without a massive budget, is this cost really worth it?
The general consensus is that any idea isn’t likely to be completely original to begin with. Facebook is just a web page that is easier to update than an HTML page. WhatsApp is just an instant messaging/SMS app. eBay was just auctions brought online. The real value of those sites are the users.
For most entrepreneurs, getting the app complete and getting users who actually use it should be the primary concern. Legal protection is an unwarranted expense, especially when that money can be used for advertising.
The bottom line, when starting out with an idea for an app, focus on making something people want to use and actually get people using it. Don’t worry about making something no one can steal, since an app with no users isn’t worth stealing to begin with. Hire a web designer and get something created people use!