Free Bangla Shadharon Ganer Boi . If you want to appear in BCS exam this small ebook can be very helpful to upgrade your general knowledge.
Go to play store and types
Shadaron gan Bangladesh by Md Nasir Uddin Morol
You can see the apps in list
Select the apps and install.
I hope you are able to read those two ebooks for increasing your general knowledge.
Thanks for reading.