The default text size can be changed in apps, though some apps deal with it better than others. There may be issues where things move around in weird ways, or (if the app is written well) things may just work out.
Unfortunately the text size is hardcoded into apps, so they all need to be individually changed.
This is a guide for version 2.5 devices, 1.0 devices are similar but not exactly the same. I have found that changing the text size on 1.0 devices tends to break the app badly, so be prepared to spend some time redoing CSS. Version 2.5 apps, on the other hand, seem to handle these changes fine for the most part.
I recommend 7.5px font size, I have found that that gives a good balance between readability and cramming text onto the screen.
Apps that I have found work with minimal to no breakage:
There may be more apps that can be changed in the same manner, but those were the ones that I thought needed the change the most.
This modification does require root ADB access.
Be sure to take a full backup of some sort, a backup of all partitions via EDL is recommended.
adb pull /system/b2g/webapps/notes.gaiamobile.orgmkdir sourceunzip notes.gaiamobile.org/application.zip -d sourcefont-size: 10px;
to whatever you want. I recommend 7.5px.
8. Time to put the app back on the phone! zip up the source and use ADB to push the entire package back onto the phone, but this time we will push it to /data/local/webapps.
cd source
rm ../notes.gaiamobile.org/application.zip
zip -r ../notes.gaiamobile.org/application.zip ./*
cd ..
adb push notes.gaiamobile.org /data/local/webapps
9. Almost there! We just need to tell the phone to launch our newly modified system app. Pull the webapps.json file:
adb pull /data/local/webapps.json
10. Change the notes.gaiamobile.org basePath value:
"basePath": "/system/b2g/webapps",
needs to change to:
"basePath": "/data/local/webapps",
11. Push webapps.json back to the phone and reboot:
adb push webapps.json /data/local/webapps/
adb reboot
Ta-da! All done!