These libraries will help you start and develop a website using CodeIgniter faster and more efficiently.

Third-Party Libraries
- Ion Auth 2 – This library is a go-to library for Auth System. It is used in many popular CodeIgnitor CMSes.
- Biostall Google Map API – This Google Map API library enables you to create a map and overlay multiple markers and different shapes.
- Ci Sitemap – Generate XML sitemaps.
- CodeIgniter-Unzip – Extract ZIP files without installing any PECL.
- CodeIgniter-Postmark – A Postmark (postmarkapp.com) library.
- CI-FIle-Browser-Awesome – A simple file browser for you to upload files and share them.
- Facebook SDK– Library for integration of Facebook PHP SDK v5 with CodeIgniter 3.
- CodeIgniter Geolocation – Library allows you to locate an IP Address using “ipinfodb” API.
- CodeIgniter-reCAPTCHA – Integrate reCAPTCHA to CodeIgniter-powered site.
- CodeIgniter Instagram API – CodeIgniter library to interact with the Instagram API.
- Refinery – This is an extension and a command line interface for the Migrations Class which helps create migrations.
- Attire – Attire Driver supports template inheritance and asset management in CodeIgniter 3.
- CodeIgniter Rest Server – A fully RESTful server implementation.
- CodeIgniter-REST Client – A RESTful client library.
- Codeigniter TwitterOauth – Integrate Twitter Oauth.
- Grocery CRUD – A library that creates a fully functional CRUD system without the requirement of extra customization to the JavaScript or the CSS to do it so.
Admin Templates / Boilerplates
- CI Bootstrap 3 – A multi-tenant website template based on CodeIgniter 3 with the integration of some useful libraries such as Ion Auth, and Grocery CRUD.
- CI AdminLTE – This template comes with an AdminLTE admin theme.
- Metronic – The cleanest and feature-rich admin dashboard template for CI.
Built-In Libraries
CodeIgnitor 3 comes with many useful built-in libraries already. So you should consider checking them before using a 3rd-party one.
- Benchmarking Class – Enable the time difference between any two marked points to be calculated.
- Caching Driver – Wrappers around some of the most popular forms of fast and dynamic caching.
- Calendaring Class – Create calendars dynamically.
- Shopping Cart Class – Allow items to be added to a session that stays active while a user is browsing your site. This library is obsolete.
- Config Class – Retrieve configuration preferences.
- Email Class – Create and send emails.
- Encryption Library – Provides two-way data encryption.
- File Uploading Class – Allow files to be uploaded with various settings.
- Form Validation – Form validation made easy.
- FTP Class – Allow files to be transferred to a remote server.
- Image Manipulation Class – Modify images such as cropping, resizing, watermarking creating thumbnails, etc…
- Language Class – Provides functions to retrieve language files and lines of text for purposes of internationalization
- Loader Class – Load View files, Drivers, Helpers, Models, or your own files.
- Migrations Class – Made database Altering easier.
- Pagination Class – Create pagination.
- Template Parser Class – Perform simple text substitution for pseudo-variables contained within your view files.
- Security Class – Process input data for security.
- Session Library – maintain and track a user’s session.
- HTML Table Class – Auto-generate HTML tables from arrays or database result sets.
- Trackback Class – Enable you to send and receive Trackback data.
- Typography Class – Format text.
- Unit Testing Class – Consists of an evaluation function and two result functions to evaluate your code.
- User Agent Class – Help identify information about the browser, mobile device, or robot visiting your site.
- XML-RPC and XML-RPC Server Classes – Allow you to send requests to another server, or set up your own XML-RPC server to receive requests.
- Zip Encoding Class – Create Zip archives.
You can see the full list and their usage on https://www.codeigniter.com/userguide3/libraries/index.html