What are some alternatives?
When comparing Atina and Flow, you can also consider the following products
Nifty Project Management - Manage projects, work, and communications in one place.
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Mind Map by RealtimeBoard - More than your average mind map
Basecamp - A simple and elegant project management system.
productboard - Beautiful and powerful product management.