Nifty - Manage projects, work, and communications in one place.

Intercom on Product Management - The ultimate resource for aspiring product managers

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.

userinput.io - Get on-demand feedback for your app, website or idea. Learn how to improve by hearing real opinions.

Jira - The #1 software development tool used by agile teams. Jira Software is built for every member of your software team to plan, track, and release great software.

ithinki - A simple user feedback tool for start-ups