FictionMagazines.com publishes monthly emagazines for electronic readers and they're looking for submissions for all their lines. Payment is royalties paid once you hit $25. The lines are:
Heater - for mystery/crime stories
New Realm - for fantasy
Nebula Rift - for science fiction
Romance Magazine - for romance
Under the Bed - for horror
eFiction - for literary
You can find all the submission details on their submittable page.