Revit Lookup is a great open-source tool to help you better understand the data in your Revit model. I use it every day, and even if you aren’t writing Revit API code, sometimes it is still useful to get “under the hood” and better understand the data in your Revit model.
You can download the source and build it yourself, but that is not for everyone. So I created an MSI Installer that you can use to install the Lookup tool for Revit 2019, 2020, and 2021. I also submitted some changes to make it easier to build Revit Lookup for any release of Revit. Jeremy wrote a bit about it at The Building Coder.
I built the installer with Advanced Installer, a very powerful and easy to use tool for building your own installations developed by Caphyon. The drag-and-drop interface lets you quickly select the files you want to install and where the installation should place them on the target computer.
Advanced Installer has a freeware version with plenty of capabilities for many Revit API developers. If you want to support them and get even more features there are three different licenses that you can purchase.