Hemingway Editor is not available for Android but there are some alternatives with similar functionality. The best Android alternative is Joplin, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to Hemingway Editor and eight of them are available for Android so hopefully you can find a suitable replacement. Other interesting Android alternatives to Hemingway Editor are Inkdrop (Paid), yWriter (Freemium), KIT Scenarist (Freemium, Open Source) and Rentry.co (Free).
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor.
yWriter is a writing tool that uses "scenes" as a unit of text and allows you to associate that text with all manner of story elements (characters, locations, items) as well as place it and rearrange it within the context of chapters.
Proofread Bot checks your writing for grammar, style, spelling, statistic and plagiarism issues and gives recommendations to improve your writing. The tool gives you a visual text editing interface and an auto generated textual report for your convenience.