[prashantganti]

(Disclosure: I am the Product Manager of Zoho Books) I invite you to try Zoho Books. It that handles invoicing, online payments via Paypal, Stripe and others, Expenses , Automatic bank feeds etc more. It is a double entry system but, that is under the hood. It has mobile apps for Android, iPhone and Windows as well. On APIs : Zoho Books has comprehensive APIs. The web client is built using the same set of APIs that we expose to developers and partners.

Please give it a try and let me know your feedback. You can reach me at prashant at zohocorp dot com