Hi, I found that viewing apngs in the usual picture viewer of your OS of choice doesn't show their animation, only opening them in the browser does - so maybe they work, but you haven't tried it in browser yet? You can usually save them as normal, we just can't always see the animation.
Similarly, Photoshop and other software doesn't detect the animation; I think it is because they're just pngs, not a specific file type. Them saving as .png is normal, the ending .apng doesn't really exist to be downloaded or selected. All my apngs are just saved as .png as well.
I don't think it saves frames similar to gifs. If I wanna edit the animation on an apng, I have to have the file I created the animation in (usually Aseprite); reimporting doesn't show the frames or animation.
Also, don't forget that GIFs have limited colors and quality. Convertig an APNG to GIF usually comes with uglier colors and quality loss.