When I am trying to access app, its showing blank/errors in screen.
Why swatches are stopped appearing in product page after change my store theme ?
When you change your store theme, files related to app also went out with your theme. Therefore you just need to go to app page and click on “Install Files” button. Which will add files in your current active theme and Second step to add short-code as per “How to Install” page instructions. If you are not able to do it. Please feel free to contact us. We will fix it for you.
Is this app also showing swatches in product collection pages ?
No. This app do not have this option yet. However if you want to do it then please contact us, We can discuss and give you price to add such feature in your store theme.
How to remove app files after uninstallation ?
Firstly, Remove shortcode from your product-template.liquid file, if you have added shortcode in it.
Secondly, Remove two script tags from your theme.liquid file.