Is there any other alternative to SQLite in Android for persisting data in the phone? I am looking something like iOS coredata or something simpler like a key-value store. If we
I don't know anything about iOS but take a look at SharedPreferences
You could serialize to xml. Take a look at Simple http://simple.sourceforge.net/ it's less then 500kb in size.
Exist a alternative call REALM is a complete library to manage the database like objects, similar to ActiveRecord (in Ruby on Rails). And one of his advantage is the speed in transactions. But be carefull because is a new library maybe is a good idea first read the all documentation.
There are a few different methods for persisting data in Android. Read this Android article about it.
If you need just a simple store for a couple key/value pairs, SharedPreferences is the way to go. If you are looking for something more powerful, that compares to Core Data, you should give greenDAO a try. Like Core Data, greenDAO a layer between your objects and the data store (Core Data on iOS usually takes SQLite, too).
You could look at http://jdbm.sourceforge.net/: 78kb jar, transactions, will save to a file.