I'm writing an android password manager application and i wish to keep master password somewhere but i'm not sure where. Must i secure the actual password the user provides me with having a hard coded password which i choose after which store it towards the database? or must i make a move else?
You shouldn't store unencrypted passwords.
For passwords, that you simply can't secure securely (because you need to keep decryption key somewhere), you need to only store a unreversible hash from it.
That method for you to compare the password towards the hash once the user provides you with the password. Whether it matches, you are able to decrypt the saved user:password pairs using the given password.
PS: Be sure to salt the hash and please do it properly.