Mappero has the right features for me: I've stopped active development now, and I've instead starting a port to Qt to make it possible to run it in the future Meego OS. But also this work is proceeding very slowly, because my free time is very limited.

I'm still happily receiving patches to Mappero from time to time, and I'm willing to spend my time to review and merge them in. So if someone want to submit a patch for a switch that would let the voice announcements come out as a synthesized reading, I'm fine with it.

What I don't like is the attitude of demanding. I've spent countless hours on this project, all out of passion. I received a fair amount of donations by some very generous users, but that's still incomparable to the efforts I've put in and the number of active Mappero users.

You are basically saying that all what I've done is worthless, if you are not donating for what you have got till now.
The feature you are asking for is implementable in about 4 hours; if I consider my official salary, it translates to about 100€. I would consider starting working on it when I receive at least 50€ worth donations mentioning this feature in the message.
But that's because I'm not interested in this feature myself; if I would, you would already have got it for free. So, if there are so many people interested in this, I would suggest either:
- collect some money, and propose it as a bounty to me or to the community
- simply convince some other developer to submit a patch for this

I hope my post doesn't sound too greedy, offensive of arrogant; it's not my intention -- it's just that when I look back to the amount of time I spent on this, and I see that most of people are just demanding new features without even saying thanks, I find really little motivation to continue working on it.