I just checked the API, expecting to find a plot(x,y) as an absolute minimum, but couldn't find this.   
To be honest, I think the following would be really appreciated by lots of people: 
- plot(x,y) 
- fillRect(x,y,w,h) 
- clearRect(x,y,w,h) 
- line(x1,y1, x2,y2)   
Could Tinkerforge team please indicate whether these will be added at a later date, or should we tackle this ourselves?    
Thanks!   
   Laurence