Apex Magazine publishes science fiction, fantasy, and horror. They publish stories directly on their website, so you can easily get a sense of what they publish. The maximum word length is 9,000 words. According to their guidelines, payment for original fiction is $.08 per word, with a cap of $50. If they podcast your story, additional payment is $.01 per word. For flash fiction, the maximum word length is 1,000 words, and payment is $0.08 per word. To learn more, refer to their submission guidelines.