TONS of Intermediate to Advanced CI content at Calm.com
Calm.com has 253 "sleep stories" (if I counted correctly) that are each 20 to 72 minutes long and read at a nice, gentle pace, and 44 of those stories are designed for children. I'd guess there's over 150 hours of content from these stories alone.
There's also guided meditation that cover different focuses like concentration, relationships, work, sleep, and others. Each category has varying amount of guided meditations and usually last 5 to 20 minutes. Lastly, there's a new daily meditation every day that is around 10 minutes.
Each of these are a series of mediations in the Concentration category.
Calm.com also has content in English, French, Dutch, Italian, Polish, Portuguese, Japanese, and Korean.