I'm now developing an app with multiple "fake" screens made with multiple VerticalArrengements, to make the transition between screens more natural, I used an extension called "Flubbie" to add some transition animat for them, but there's a problem, it works for most of modern devices runs Android 3.0 and higher, but it will throw me an error when it runs on android 2.3 or below, so my temporary solution is to disable the animation when the device's api level is below than 11, that makes transition between screens look very weird, so I need a better way to do so.
I'm encountering the similar problem when I'm using MakeViewUp extension to create ripple effects on my app, it throws error when the device's version is below Android 5.0 and devices below Android 10 is ignoring the ripple effect's color, it shows dark grey, I made a temporary solution for pre-5.0 devices also, it will act like Android Holo effect which turns the whole button into accent color, which creates similar effect to my ripple effect, but I want a more natural way to recreate ripple effect no matter which version of android is being used, (I'm not using the "Device Default" option which makes translucent buttons look weird with shadows, and the shadow is unwanted even if the button isn't translucent.), is there any better solution?
maybe you can use javascript library for that
Is there any compatibility/performance issues when using these on older devices with outdated softwares installed on them? I'm trying to make my app work for every devices including classic devices, I made a simple research about how to use JS libs on App Inventor and there's a way to use WebView to run them, I'm afraid that WebViews may cause compatibility (May not work if webview provider is outdated or not installed?) and performance issues.
And do I have to rework the previous written codes which have nothing to do with animations?
Your issue is probably that the extensions functionality/technical content is not supported on very old devices (usually before Android 4).
As you have done, you will need to introduce workarounds for these features.