Thanks for the download.
I downloaded and tried it out. (Linux 64bit version.)
I expected a SMALL utility for quickly view textures with normalmaps. But the program is almost about 415 megabyte. Ten times more than my expectation for a tool like this!
And it is just the 64bit version, because the download include both 32bit and 64bit for some reson. So you need about a gigabyte space to decompress the ZIP. I think everyone will use the 64bit, maybe one or two people on Earth will download the 32bit. No-one want to download something twice, just than to delete the half what isn't needed. Wasting of download time and also storage space.
What is this weird look? It would be better if it looks like a normal program, that have normal looking windows and menus and text, the same as a theme that you use in your system. Like 99% of every other software tool.
Not to mention it can't load DDS texture files, which is de facto the most basic and useful texture-file format, IMO.
I did not bother to convert some texture and normal map to any other format, so I can't tell that only the DDS files not work or the program itself can't load anything.
AND WHY a simple viewing utility need to acess the Gnome keyring? For what reson?
So my answare to your question is that I really dislike your program. Useless bloatware. Or worse...