I've used both Trello and Jira, both are very user friendly and can help manage tasks. Jira uses a ticket system to assign and track tasks which can be helpful to keep on task and set goals for each sprint.
I'm looking into using Trello for both the group and personal project. I found that it is very similar to what I use in the workplace at John Deere.
Though I am not using it, I have heard good things about monday.com or rally.
I like to just use my brain. An infallible platform.
I like trello, it is free and very easy to use. Plus you can have cool backgrounds for your task boards!