1. Reverse-Process Screen Calibration:
Problem: conventional screen calibration requires one to precisely stab the centre of each onscreen target. No matter how hard I try to aim I always miss the exact centre of at least one if not several of these targets. As a result the screen is never accurately calibrated & doing things such as freehand drawing with the stylus can be a real pain.
Proposed Solution: An app which calibrates the screen by the user holding down the stylus on the screen *first* & then using the direction buttons to move the crosshair to the point where you want the unit to register it (the following release of the stylus or the pressing of the enter button when you are happy that these positions coincide could then log the relationship). This would then be repeated around the screen until you are entirely satisfied with the precision across the screen.
Multiple Undo & Redo so if you make a mistake you need not start from scratch.
Presets so you can immediately switch between certain calibration settings depending on your drawing task (e.g. another calibration setting registering the projected point of contact of the stylus with the display if the stylus tip were pointed & not rounded, & another to compensate for the parallax error between the face of the touch screen & the perceived position of the face of the display beneath, etc.)
2.Dead Subpixel Neutraliser:
Problem: Bad pixels can be very annoying. Where the screen should be one colour at a certain position you may have a glaringly bright dot in a different colour as a result of one or two dead subpixels.
Proposed solution: An app which would allow you to specify to the Zaurus/Simpad/etc. the precise location of each badpixel (e.g. by using the direction buttons to control a crosshair). The enter button would then be used to log each position. The app. would then completely shut off each bad pixel (to an innocuous black dot), followed by a preview of the result tested against solid backgrounds of each of the three pixel primary colours. If you are satisfied the app. would then allow you to permanently patch the system (preferably in a manner independent of OS so you need not redo with each new reflash).