<a href="http:&#x2F;&#x2F;creately.com&#x2F;plans" rel="nofollow">http:&#x2F;&#x2F;creately.com&#x2F;plans</a> only costs $50 for a year for an individual<p>It allows you to create use cases. I wouldn&#x27;t get too much into the details. It&#x27;s a designer and developers job to design and develop. If they are good they will have plenty of insights on &quot;how&quot; to do stuff. If you give them too much detail they will just use your design. Let them use the other tools to create the design and flow for you. And let them justify why they made those decisions.<p>I would design the initial on boarding flow first and test if you can get users for it. don&#x27;t spend a bunch of money on a project that can&#x27;t get bunch of users.