Accounting

If you are a graduate then you can pursue MBA.
All the best.

You can join some professional course in Accounting like ACCA. ACCA stands for the Association of Chartered Certified Accountants a leading international accountancy body. The ACCA qualification is recognised and is treated in other countries as being equivalent to their local qualification
Here is the link:
http://www.accaglobal.com/in/en/about-us.html
I hope this would suffice. All the best and god bless you.

After B.Tech, M.Tech is the most appropriate option.

There is no such application for PC but you can learn from the following websites like Coursera, Edx, Udacity, etc. Some of them provide free course and certification courses are very good.

According to my suggestion the priority whatever has to be chosen related to your idea and enhancing capability skills if you want to become an expert in finance or accounting we can go for many options like:
Masters in accounting and taxation
Chartered accountant
Masters in auditing tax consultant
These many options are available because nowadays demand is more in finance based on auditing and taxation levels, you can do online courses too depending on accounting.