Taxumo is a software-as-a-service or a system that is stored in the cloud, which means you can access it anytime, anywhere as long as you have internet connection. 

Compared to BIR's eBIR forms, Taxumo (the system) (1) automatically computes your tax dues based on the income and expense entries that you encode and the settings/information that you saved, (2) automatically fills out your forms; and (3) allows you to pay directly and ONLINE through Taxumo's wide array of partner banks, so there is no need to fall in long lines at the bank. In a nutshell, we are here to help you fulfill your duty as a tax payer in the most convenient and hassle-free way! :)

Related question:
​If we use Taxumo, do we need to file using eBIR Forms?

No need to use eBIR forms. The taxes that you file in Taxumo is directly submitted to the BIR.