Settings → About phone

• Yes
• Have to try
  • https://play.google.com/store/apps/details?id=com.github.axet.hourlyreminder - Hourly Reminder
  • https://play.google.com/store/apps/details?id=chime.me.big.ben.free.emad - Chime Me Big Ben Free
• No
  • https://play.google.com/store/apps/details?id=com.caynax.hourlychime - Hourly chime
    • Has a pro version (meaning the free version is not good enough)
  • https://play.google.com/store/apps/details?id=it.nadolski.blipblip - Blip Blip (hourly chime)
    • Has a paid version (meaning the free version is not good enough)

• MacroDroid - Device Automation
  • https://play.google.com/store/apps/details?id=com.arlosoft.macrodroid
  • Can this be used to chime every half an hour?

• https://play.google.com/store/apps/details?id=com.teacapps.barcodescanner - contains ads. See if you can find something that is functionally equivalent but ad free.

• https://play.google.com/store/apps/details?id=com.mobilityware.Sudoku
  • It is 40 MB which is a lot for a sudoku game.

• https://play.google.com/store/apps/details?id=com.Appgeneration.Sudoku
  • It is 59 MB which is a lot for a sudoku game.
  • I did not find a 6×6 version
  • See if you can find something that is functionally equivalent but better