There is an app called Bazur, an updated form of the earlier Avzag app, Raxys Studios has been steadily building a great library covering many languages from the Caucasus region.
This site is a great place to learn about other aspects of Ossetian culture and history, in addition to some language learning links:
http://ossetians.com/eng/index.php?showcat=jump&f=35
I've also found a couple of links to the more well-known papers on the Ossetian Language, including V. I. Abaev's seminal work:
https://www.azargoshnasp.net/languages/ossetian/ossetian.htm
There is also a subreddit, r/Ossetia-Alania, a small but dedicated community who share about topics related to the language and other facets of all things . There is also my own subreddit, r/CaucasusLanguages, to discuss the language but also foster connection with learners of other Caucasus Languages.
Available in the Play Store, and on Youtube; 'Ирон Чиныг' which allows you to listen to, and follow along with, stories written and read in Ossetian. Even if you are not studying, the reading is clear and pleasant to listen to, I enjoy it very much.
Here is a site recommended by one of our own, https://iryston.tv/ir/, an Ossetian Media-outlet, plenty of different materials to expose you to everyday Ossetian, as opposed to the often stuffy writing of academic literature. Complimenting the Iryston website is the Iryston Youtube Channel, it offers an extensive list of playlists with some of the playlists themselves containing videos in the hundreds. The series I am currently enjoying is 'Хæзнагæс'.
I found a great flashcard style website, that includes basics such as numbers and days of the week/ months of the year.
https://www.masteranylanguage.com/c/r/o/Ossetian/FlashCards
This video is a language comparison between Modern Persian and Ossetian, they also talk a little bit about the etymology. Enjoy!
This video goes with the video directly above, as it includes one of the contributors to that video, Saeed Bazkhaneh, it also features an Ossetian speaker, Timur Chibirov, who speaks to the Ossetian perspective. The balance between the two gives an excellent snapshot of Ossetian within the sphere of Indo-Iranian Languages.