I am unable to find the localization files for the Icelander theme. Only locale sk_SK seems included in the /language directory. The wordpress.org link to obtain more localization files in the readme doesn’t work anymore.
To explain, the file you are looking for is languages/icelander.pot. The sk_SK.po and sk_SK.mo files are already translated versions into Slovak language. There is no more translations of the theme available currently, so you will need to translate it using the aforementioned instructions.
Also, please note that the WordPress.org link only works for free themes hosted on WordPress.org. This is clearly stated also in the readme file. As you have obtained the theme from ThemeForest, there is no translation repository available for the theme at WordPress.org. Thank you for understanding.