I have an experience using Source Tree with Mercurial.

We can use Source Tree to use GitFlow with UI instead of firing commands in command prompt.

Reference links:

1. How to use Source Tree with GitHub – (https://www.youtube.com/watch?v=YwekKdd79lk)
2. Git Flow Part 2 – Using Git Flow in Source Tree Tutorial (https://www.youtube.com/watch?v=z53JJ7P78Vc)

Download Source Tree for Windows : https://www.sourcetreeapp.com/

This is an example screenshot how it will display with the use of Source Tree. Actions like Crate Feature, Create Release and Create Hotfix branch are done using GitFlow.

Source Tree with GitFlow