My worst habit is roasting nuts in the oven and forgetting about them. I can't really see them through the oven door so I also need to open the door (releasing heat in the process) to check and stir them. I hate the timer on my oven (so does the dog - he hates beeps) so I never set it but if I am busy elsewhere getting other things done, the sheet of whatever in the oven may get a tad overdone. Additionally, one often should stir the nuts so they are evenly roasted. If I do nuts or seeds on the stove, I don't leave it to do its thing so that consumes me while it is happening and nothing else gets done (though it is much faster that way and I probably get more consistent results).
I think a separate device designed specifically for roasting nuts, seeds and spices may be the answer to both issues - especially since it likely would have a lower temperature range for perhaps a slightly longer time period and stir itself. The longer time is offset by the fact that I would not be throwing out spices and nuts. I am sure you would have to do a lot of testing but perhaps you could include a rotary dial that auto-sets the device for optimum times/temperature for either nuts or seeds and is so labelled but that may be getting too complex for the time being. I would rather reset the device for another round of heating than take burnt nuts out of my oven or try to juggle both stirring a pot with one hand and swishing around spices in a pan with the other. Spices often need to be ground after toasting, so a small appliance for toasting them first that could sit right next to the grinder would be useful. Just don't make it too tall or heavy (storage issues then ensue). Ideally, I would like something small enough to store in a deep-ish drawer near where it is used the most.
I don't currently roast too many spices or nuts - just occasionally/perhaps once a month on average - but my current interest in preparing more Indian dishes at home could easily make this potential device much more useful to me given that I have a ('unadmitted' on this forum till now) propensity for messing up the small stuff like this. I am sure no one absolutely NEEDS a gadget such as this but many of us are kitchen gadget junkies so there is probably an audience here.