When comparing Gitit vs SynapBook, the Slant community recommends SynapBook for most people. In the question“What is the best cross-platform note-taking app?” SynapBook is ranked 12th while Gitit is ranked 36th. The most important reason people chose SynapBook is:
Using the tree structure, you can structure the content.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Lots of export formats
Giti has a multitude of formats that it allows to be exported, including LaTeX, ConTeXt, DocBook, RTF, OpenOffice ODT, and MediaWiki markup.
Pro Supports markdown
Getit supports markdown, a plain text formatting syntax that is designed so that it can be read by HTML.
Pro Free and open source software (FOSS)
Licensed under GPLv2 so you can download source code and customize to meet your needs, provided that you know or are willing to learn Haskell.

Pro Can be used collaboratively by multiple people

Pro Renders math
Using MathJax.
Pro Memo can be structured in tree form
Using the tree structure, you can structure the content.
Pro Nice sticky memo UI
It can support pop-up notes which can be used like simple Windows Sticky memo app.
Pro Both search-based Memo and organizing tree Note
Search-based notes and tree-oriented tree notes are supported separately, so can be used conveniently depending on the purpose.
Pro Offline mode support
Basically, it is based on server synchronization, but it can be used offline.
Pro Folding
Groups can be folded.
Pro Various text styles and decorations
General styles (bold, font size), highlighter and separator line, and more.
Pro Frequent updates
Bug fixes and additional new features rolled out frequently.
Pro Free
Cons
Con Requires Haskell
On some Linux platforms a binary package for Haskell may not be included in the standard repositories. So, it will be necessary to compile Haskell from source code or find a non-standard package repository, which may seem like a hassle if you don't use Haskell for anything else.
Con Does not support iOS
This app only supports Android and desktop OS, but not iOS.
