Most of our software need is actually can be fulfilled by many already existing general Application. Take Text Editor and Spreadsheet for example, they are very general but highly useful piece of software. You could use them to store any kind of list or database if you can still accept the very generic feel of them and awkwardness when things get bigger. You can even utilize folder structure, file naming convention, markup convention, built-in search and replace capability to "emulate" an app.
I think we usually underestimate on how far we can go with the already-existing software and too quick to grab specialized software. But in this age of so many existing option, with many even free, who can blame us?. However, we need to also realize that adoption has it's own hidden-cost/restriction/negatives that sometime more generic application has better performance e.g: IDE vs. Emacs cases.
So, to take the best of both worlds, I guess the heuristic would be :
- Being really comfortable with available generic application. To be concrete, master application like powerful Text Editor (I use JEdit, there are others who uses Emac's fanatically) and Spreadsheet. Use their advanced feature. You will encounter that when knowing them deeply you'll find many cases that they are just suffice.
- Browse around and keep an eye on less widely used but powerful generic application. For example, despite it looks to have a specialized use, I find Freemind really useful in a wide variety of situation.
- If it seems enough to use the generic one in certain case, try the generic one first rather then trying to find other more specialized app, you might find out that it is actually do enough.
- When things get rough and you really feel that you need a more specialized app, shop around and pick the one with the most generic functionality. For example, when you only need to edit picture and Paintbrush looks plain, something like Paint.Net would be more suitable than beating yourself up trying to be graphic designer by using Gimp.
- When you finally use the new app, push it to it's limits and see what else you could utilize from it. Later, you could mix and match your software based on what each can do. You will have less software to deal with but still get the job done.
From the perspective of developer, it is useful to see what existing software that already exist that already usable enough to solve the current problem you are trying to solve with developing this new software. Developing more specialized (or more robust) software will cost the user the utilities/familiarities that he/she has on the generic app so you'd better give something much better in return.