Flash Feature

Blink Ink
http://www.blink-ink.org/

Home to the finest in contemporary 50 word fiction. Archived in the Beinecke Rare Book and Manuscript Library at Yale University, Blink Ink is a quarterly print journal publishing the best in stories of approximately 50 words since 2009.

The current prompt or theme is water.

http://www.blink-ink.org/submissions/

Journal of Compressed Arts
http://matterpress.com/journal/

https://matter.submittable.com/submit

The Journal of Compressed Creative Arts is a non-profit publisher of compressed creative arts, such as micro fiction, flash fiction, prose poetry, compressed poetry & visual arts, and whatever other forms compression might take. Matter pays authors $50 for their accepted pieces. We publish weekly bursts of compression & decompression and make as many varied word-plays on matter as we can. We also blog at FlashFiction.Net. 

Though submissions are currently closed until mid-September they do something called topical Thursdays.

Friday Fix Fiction
https://www.fridayfixfiction.com/

offers a visual prompt/theme which the author composes and sends in. From the website” At Friday Fix Fiction, our goal is to write a complete story in fifty words.

The above journals are looking for quality submissions—consider sending your work!