What does "Third Party Applications" mean?

First Party is the OS manufacturer, for example Microsoft with Windows. Second Party is the user (you). Third Party is the manufacturer of other software or hardware, e.g. Adobe with Photoshop and Flash.

A third party is an entity that is involved in some way in an interaction that is primarily between two other entities. 

A contract might be, for example, between a software company that creates a mobile app and an end user. From the company's perspective, it is the first party and the end user is the second party; from the end user's perspective, those positions are switched. The third party in this example might be a marketing firm or an ad network. 

The third party may or may not be officially a part of the transaction between the two primary entities and may or may not be interacting transparently and/or legally. Here are a few more examples of contexts in which third parties are mentioned:

• Eavesdropping is the covert interception of a private communication between two individuals by a third party.
• In a man-in-the-middle attack, a third party intercepts communications between two parties, usually an end user and a website, typically to access user data.

• A third-party cookie is placed on a user’s computer by a website from a domain other than the one the user is visiting.

• A 3PL (third-party logistics) is a provider of outsourced logistics services.
• A managed IT service is an information technology (IT) task provided by a third-party contractor. 
• An open relay (sometimes called an insecure relay or a third-party relay) is a SMTP email server that processes email messages that are neither for nor from any local user.

Third party applications are those which are not made by the manufacturer of the OS who is the first party, but its made by other developers who publish their applications on the markets provided by the OS manufacturer which makes them the third party.

Third party applications are programs written to work within operating systems, but are written by individuals or companies other than the provider of theoperating systems

- The applications which are developed as components of  an original software.

- They basically provide an additional feature/function to the primary software.

-These applications can be freely distributed or sold.

- They are developed mainly because the end-user can specifically select an application which he/she finds it useful.

- This allows the software developers to avoid burdening the basic software with all possible functionalities hence improves its performance.  

A Third Party Applications Means ,  a reusable Software Application developed to be either freely distributed or sold by an entity other than the original vendor (OEM) of the development platform. The third-party software component market thrives because many programmers believe that Component - Oriented development  improves the efficiency and the quality of developing custom applications. Common third-party software includes macros, bots, and software/scripts to be run as add-ons for popular developing software.

These are applications that are provided by a third party and that are required to support the requirement of the first and 2nd party who are the major contract or project holders. 

Third party applications usually fill the gaps raised by clients requirements and that the primary party doesn't provide or offer. It is common that these applications are authorized and qualified by the primary/mother partner to integrate and deliver and most often can't operate as a stand alone application.

Example: In my case i have iphone which is made by apple,and i wanted to install an application which is not made/authenticated by apple it self but still i can install it but as a third party application.

Third party applications are those which are not made by the first  but its made by other developers who publish their applications on the markets provided by the OS manufacturer which makes them the third party.

Application that is not developed by the manufacturer of the device which you are using. The application that support the comminucation with the devices manufactured by others. Basically application uses some standard communication protocol irrespective of the product manufacturer.

Third party refers to a another company making software for the original vendors product. For example: nearly all iPhone Apps are created by third-parties (not by Apple itself)

3 party application is the application distributed freely .Any venders can provide 3rd party applications which does not depend up on manufactures laws and orders