We do not currently have an "analysis" function in Time Master. It is something that has had several requests and we will very likely add something in the future, but we do not have an ETA for it yet.
One thing that I'm not clear on is if you are billing a "Fixed Amount" for your projects? If you do, then you would create a Project that has the "Kind" of "Fixed Amount". When you have completed the project, you would mark it is "Completed" and only at that point would it be available for invoicing. Your client would only see the Amount, but no duration. On your device you would still be able to see how much time you actually spent. You can check to see if you were over or under your estimated time. You could put your estimated time in the Project Note field so you can compare that to the actual time when the project is completed.
I'm not sure if that answers your questions or not, so please feel free to write back on this.