When I finished my studies and started working on my Ph.D. thesis, I could not found a good tool to administer my many documents and sources. Because of the mathematic formulas, I wanted to write my thesis in TeX / LyX and use BibTeX to create the list of references. Quickly I had pretty clear idea what a good tool would have to look like: fast, small and easy to handle, with some export- and import functions to transfer the data. I started to develop "WibTeX" in Delphi, the Turbo Pascal descendant.
With time, more and more functions were added, for instance the download of cover pictures for books, or the key word manager. All in all I published 7 major versions of WibTeX, the last in 2013. This version can still be downloaded from this site.
Because of work and family obligations, I had to suspend further development of the application. Moreover, I could not afford the expensive licenses for newer versions of Delphi (Embarcadero). It was only in 2019 that I discovered Lazarus, the free IDE for Free Pascal. I completely rewrote and modernized the source code, especially given that Microsoft and the creators of Libre-/OpenOffice now have integrated native functions to administer sources and create lists of references - something that did not exist in the early days of WibTeX. The new version of WibTeX therefore only provides the interface to transfer data, rather than sending commands to theses applications as before. WibTeX is now also available for platforms other than Windows (Linux; MacOS and Android forthcoming).
Well, I recognize that meanwhile there are other good document managers out there. However, WibTeX has some functions that other might not have - and vice versa. WibTeX does not require any run time libraries or Java environment, since it works with native binary code. I guess you should just try WibTeX to see if it fits your needs!