To speed up reviewing on mobile I modified Mempo’s (thanks) userscript to use buttons.
It looks like this (screenshot taken on desktop): 
In order to load this userscript, I created a WebView in an iOS app using Xcode on a VM… it sucked. I neither know web or iOS development, plus I have no developer account to put this app on the AppStore. However, it can be installed using Cydia impactor or on jailbroken devices.
Here is a link to the userscript.
A lot can be improved - I’m still ashamed about how I created three spans because I did not know how to increase the span’s height using CSS. However, the app is somewhat working and I can finally get many reviews done mobile without it feeling exhausting.
You can download the IPA here.