Flowable Task App - change presentation of a process

Hey there,

my goal is to have a new presentation of a process (incl. forms) in the Flowable Task App.

What I have done so far:
I designed a process with forms for the User Tasks and conditions at the sequence flows (outgoing of the gateways). I used the Flowable Task App and the process is runnable.

Now I want to make the execution of the process more user-friendly. Following steps are wished:
Instead of Radio Buttons have two big buttons which lead directly to the next User Task.
Then, have a one step back button so you can go to the last executed User Task.

First, I was thinking about changing the Flowable Task App, but I don’t understand the structure. More and more I read about the Flowable Engine, but I don’t understand enough to design a Flowable Task App on my own.

Can you suggest an easy way for this problem?
If yes, can you give me explanations, hints or websites to solve the problem.

See: Serendipity