Hi,
I am a professional android app developer with over 2 years of experience in android app development.
I have fluency in both java and kotlin.
I've worked with android studio and adobe xd for ui design for a long time and have pretty much knowledge on material designs.
I just saw your issues,
Now let me try to give you some solutions,
Firstly the loading icon can be changed and animated very very easily, I can do it for only 5$.
Secondly the webpage being slow is totally normal, because a webview is not the best approach for doing what you're trying to do . I would suggest making a progressive web app or pwa, which is obviously faster than a webview, because for making website to android apps webview becomes a bit slow. I can do this part for only 15$.
Thirdly,
I can also implement the print option, it's actually very easy,
For that part you just need to first load that print file into the webview, then you need to create a print job and it'll print out the document easily for you. I will charge 15$ for this as well.
If you're interested, please message me and I will get back to you.
Thank You
Best Regards,
SharifRafid