I have been looking for a good invoicing system for my clients for a while, I have bought a few tools (LTDs) that either focused only on invoicing or had some invoicing functionality, none of them have come close to Deskera, except one, Kashoo, to a limited extent. Deskera has so many appealing invoice templates and the ability to upload your own template is fantastic.

Firstly, the android mobile app is elegant, smooth and fast - easy to navigate.
Secondly, the system does not just do invoicing but you can do your complete accounting as it includes chart of accounts, capturing of expenses and producing financial reports.
Thirdly, there is a CRM module and a payroll / people module which I am yet to explore.
Fourthly their support is amazing, the response and implementation of requests is fast.

What I would like:- scanning of expense invoices with OCR, increase in power users