We all know that reserving your EC2 instances can save you some substantial money of your AWS cost. But I personally found it hard to keep track on which of my AWS Amazon EC2 instances had reservations and how long they were still valid.
So far the Amazon console only gives you insights what instances you are running and which reservations you own. But a reservation is not directly attached to a running instance - instead there are 3 parameters instance type, scope(zone) and platform coming with each reservation and if you have a server which is matching those it will be running on the reduced rate of the reservation.
I did this with a spreadsheet until I decided to build myself a little tool using JAVA and the AWS EC2 SDK - and the result was https://www.ec2saver.info/ - this website is far from complete and I have lot of ideas what to add but I think some people might like it already at this point.