The latest Pro Tips blog post covers methods of using Lansweeper for IP address management. While there isn't an IPAM module in Lansweeper, with some advanced reporting you can get some interesting data.
If you're looking for more ways to tackle IPAM with Lansweeper, this topic also has some interesting ideas: https://www.lansweeper.com/forum/yaf_postsm64652_So-close-to-providing-IPAM-capabilities.aspx#post64...