Hi Sunny,
Let me introduce myself.
My name is Fabio, I'm from Brazil and I've worked developing projects in the most different areas.
I'm a backend and frontend programmer.
I have 10+ years of experience with Java technologies, building solutions using JSE, JEE and J2ME.
Over 5 years of project coordination.
5+ years of experience with Android.
3+ years of experience with PHP, MySQL, PostgreSQL, HTML, CSS and Ajax.
You mentioned in the description you want the freelancer to develop a own barcode scanner.
I've used ZXing in many project without problem.
It is an open source project that allows developer to incorporate the code for barcode scanning.
For me it always worked good and fast.
If you want to discuss more about the project, please, feel free to contact me.
Kind regards,
Fabio Bergmann