There are many sites that offer free hosting or free domain, but rarely both, so I recommend you to search for a precarious hosting such as hostinger or webhost to acquire a free domain, for example in link give away domains with extension .tk
which are easy to configure with the tools of the two sites that I mentioned.
(I'm not sure they have a codeigniter because it has enough that I do not use it)
Normally these sites have the cpanel
tool that contains administrators to configure the site, from email accounts, ssh certificates, referenced domains, subdomains, ftp accounts, databases, and plugins.
My sincere opinion is that if you are going to extensively and for a long time use web hosting for profit in mind, invest in a paid site that includes you and both aspects, for example, hostgator, because normally these services are endeavored with your customers.
Alternatives of third world students c # $% # $% and luchones, enfierrados and altered
Being a little more sincere and brutally frank, for your student projects you will not normally need a service that is available 24 hours a day and support more than a thousand people at the same time, especially if you are not going to receive the most economic retribution Therefore, the cheapest option is to choose one of the following options that will make you learn and give you the width for any technology you choose.
You can use services like noip.com, which allow you to have a DNS server pointing to your personal computer, if you open the ports of your modem / router and run your program a few minutes before you need it you will be able to access your computer with a miservidordeestudiante.noip.com
domain from at least your country and a few nearby countries. Supports normally about 9 people at the same time without affecting the performance for everyone (including your personal computer).
My favorite option, although a bit more complex and reckless is to use TOR with Vidalia (they go down in the site of the tor, before they came together but now they separated them) that will allow you to make your computer become a web server in the darknet TOR, a pseudo paradise for hackers, your site could be anywhere in the world from this darknet, your address is generated something like link and It will be accessible whenever your pc is on, you are connected to the TOR network and you are serving pages with vidalia. Its only disadvantage is that since all communications are encrypted and redirected it is very slow ... it's like the Internet in the 80s, just before google appeared.
The last option is something similar, using freenet, another less popular darknet you can mount your server and achieve higher speeds depending on the number of people who consult and are connected to this darknet. It has the advantage that it has its own separate program to configure the server, as an advantage the freenet normally does not consume as much bandwidth as the TOR.