Every fiction writer has a character development sheet, including me.
My own character sheet has been put together over the years and it suits my needs. My friend and fellow author Iulian Ionescu developed a rather detailed spreadsheet on characters and recently shared it on his blog. You can get a copy and read what to do with the spreadsheet here: http://www.iulianionescu.com/blog/character-development-worksheet/
I tried it on a few major characters from my new novel and discovered a new facts about the characters that I didn’t know before. Now I plan to expand its use on my next novel. Iulian’s spreadsheet doesn’t replace my own character development process but it does expand and supplement it The spreadsheet also helps develop the characters role within the story by asking questions on the story context and the character arc.
If you’re a fiction writer, I highly recommend using Iulian’s spreadsheet.