This will be fixed in the upcoming app version 1.3, which I'll release as soon as Apple releases the corresponding iOS update.
The fix might change font sizes that you set on an Android device at half the size. If this is the case, you can tap Help > Troubleshooting > Update Font Sizes in the Android app to rescale the existing sizes. If you set some of your font sizes on Android and some on iOS, you would only want to use this function if the majority of the font sizes are incorrect, because you will then have to manually update the rest.
Once the sizes are set the way you want them, then the scaling across devices should be automatic after that.