No. ROKKR the company (developer) does not provide content. They only provide the player. All URL lists are third-party.
If you search for "rokkr url list free," you are likely looking for a curated collection of links that you can paste directly into the ROKKR app. Here is why these lists are the lifeblood of the platform: rokkr url list free
For free lists, every 3–5 days. Bookmark 3-4 sources so you can rotate when one dies. rokkr url list free