On a touchscreen phone like the SE P1i, it sports really large buttons that you can tap with your fingers without problems, if you like to do so. On the SE P990i in flip-closed mode, the four-way pad is used for entering operations and asking for the result, in the style of calcium, a freeware calculator for S60.



e.g. Sony Ericsson P990i, P1i, M600, W950.
The program is not signed, not even self-signed, and will warn you about this when you install. If you don't trust me, don't install.
Note: The program probably won't work on the Motorola Z8 and Z10 models, because of different keyboard scan codes that I was not able to test. And before you write me an e-mail asking for this or that additional feature, please remember: TouchCalc is meant to be simple and easy...