i have a similar experience, i'm running a free Barcode Creator software, it's the best free ever in the market.
I used adsense with it and it made $670 or so the last year, not so much but i think better than what donations can make. (I have few traffic 200 unique a day)
Charging for it can be good, the application need to look professional and priced correctly. you'll have other few things to look into, like how payment will be made, supporting your users...
I was very busy for the last while or i would make a pro version and charge for it. So my advice : Go for it!
I used adsense with it and it made $670 or so the last year, not so much but i think better than what donations can make. (I have few traffic 200 unique a day)
Charging for it can be good, the application need to look professional and priced correctly. you'll have other few things to look into, like how payment will be made, supporting your users...
I was very busy for the last while or i would make a pro version and charge for it. So my advice : Go for it!