My experiments have found I can sleep the first night but the second is impossible, quit and restart is the only option. Android 4.4.2 Asus Transormer pad.
https://youtu.be/bh46MK5qTJ8
(Is there a way to separate the PC and PE bug searches as the results are cluttered with PC ones and is resulting in duplicates)
My son had the same problem with his old tablet. Has your son made a lot of worlds? I found deleting or cutting out of the 'games/com.mojang/minecraftWorlds' folder and pasting the in a back-up folder cleared the problem.
"The name is now a base64 representation of the real name so you can have world names in any language. You can find the true name inside level name.txt"
quoted from shoghicp's reddit post.
https://www.reddit.com/r/MCPE/comments/34w1w6/minecraftworld_folder_names_in_011_beta_89/
You can rename the folders without any ill effects.
This only effected that build and should be marked as resolved.
Confirmed on Asus Transformer Android 4.4.2
I think this bug is related to MCPE-8363 as there appears to be a crash issue associated with falling blocks i.e. sands and gravel. When these items fall or are picked up crashes sporadically occur.
Still effecting beta 8
https://youtu.be/_fRk3kimRJw
No it's not fixed, all worlds still displaying as being played 'Today'.
After restarting my tablet after a few days it appears all the world's have gone back to all showing played Today.
Android 4.4.2 Asus Transformer Pad
Appears to have been fixed in build 5 my device is displaying worlds as it used to.
Inside each world folder is a 'levelname.txt' file with the name you gave it.
The screenshots appear to show houses that are correct please check the wiki:
http://minecraft.gamepedia.com/Minecraft_Wiki:Projects/Village_Blueprints/Farm_Shack
See V1 variant
Confirmed on Asus transformer pad. android 4.4.2. Version 0.13.0