[docs] global: update readme

readme.md

@@ -4,9 +4,9 @@
 
 ## About
 
-Tracking objects in video recording can be tedious. Existing software are expensive, the learning curve can be steep, and the workflow can not be easily adapted when the project evolved.
+Tracking objects in video recording can be tedious. Existing software are expensive, the learning curve can be steep, necessitate a powerful computer, and the workflow can not be easily adapted when the project evolved.
 
-**FastTrack** is a desktop tracking software, easy to install, easy to use, and performant. The software can be downloaded and modified to adapt to any needs. The core of the software can also be embedded easily in any C++/Qt project.
+**FastTrack** is a free (as freedom) desktop tracking software, easy to install, easy to use, and performant. The software can be downloaded for Linux, macOS, and Windows, and a public API is available to embed the core of the software in any C++/Qt project.
 
 Two main features are implemented in the software:
 * An automatic tracking algorithm that can detect and track objects (conserving the objects' identities across the video recording).
@@ -21,15 +21,19 @@ Stable builds of the software are available for Linux, Mac, and Windows on the [
 ## Documentation
 
 User documentation can be found [here](http://www.fasttrack.sh/UserManual/docs/intro.html) with video tutorials, examples, and an extended description of the software.
-Developer documentation can be found [here](http://www.fasttrack.sh/API/index.html), it contains information to set up a development environment and the API of FastTrack.
+Developer documentation can be found [here](http://www.fasttrack.sh/API/index.html). It contains information to set up a development environment and the API of FastTrack.
 
 ## Examples
 ![alt text](docs/user/assets/example.gif)
 
 ## Contributing
 
-If you want to contribute to FastTrack, please follow the [guidelines](contributing.md), any contribution or idea is welcome.
+If you want to contribute to FastTrack, please follow the [guidelines](contributing.md). Any contribution or idea is welcome.
 
 ## Get help
 
-If you need help, please contact benjamin.gallois@fasttrack.sh or [gitter](https://gitter.im/fasttracksh).
+If you need help, please contact benjamin.gallois@fasttrack.sh or open an issue on GitHub.
+
+## Citation
+
+You can cite FastTrack [Gallois, Benjamin, and Raphaël Candelier. "FastTrack: An open-source software for tracking varying numbers of deformable objects." PLoS computational biology 17.2 (2021): e1008697.](https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1008697).