VPC Tracker is a tool that collects and helps you manage your network CIDR ranges at a central place. No need to keep an Excel sheet on all your VPC network addresses allocations.
No gateway launches required. Just add all your other AWS accounts on the Controller, VPC Tracker will retrieve the information.
VPC Tracker auto updates once a day. You can do on-demand update by clicking the refresh button.
If you are planning to create a new VPC, you can first check CIDR overlap by entering the CIDR block and click Test. The result displays the overlapping CIDRs for your reference.