OpenXava - OpenXava is a Web Java Framework for Rapid Development of Enterprise Applications.
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.
Zoho Creator - Zoho Creator is a low-code application development platform that helps you build a custom, mobile-ready apps to run your business.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
zeroqode - Build your app up to 10x faster with no-code app templates
hiTask - HiTask is a free shared task list for your team. The place to plan, organize, and stay in sync.