I'm a developer and I work in my spare time on a small mac app: http://totalfinder.binaryage.com Current stats:
I'm new here and I saw some nice mentoring answers under other questions. As being one-person-wannabe "startup" I quite feel I'm losing focus and lack feedback. I'm going to charge for my product for the first time so I want to avoid obvious mistakes... which more experienced of you may see.
What would be your advice for me to focus on at this stage? Thanks.
Your 0.9 version is the beta. The 1.0 will be the first release. You don't typically charge for betas at this scale. If there will be code changes between .9 and 1.0 release a .95 that is code complete for 1.0.
It is unfortunate that you already are displaying a price of $15 as I'm assuming you did not do any market research or customer survey. You might have 20% fewer people willing to pay a 40% higher price. Keep that in mind next time.
Focus on having great docs, FAQ and forum as you near release. It sounds like you have some good numbers going. You should be off to a good start. Make the product great so you have good word of mouth. As you get user feature requests going forward don't just take what the user asks for straight, but make sure you are understanding why they are asking, what it is they are trying to accomplish, because you may be able to find a better solution than what they suggest.
Moving from free to paid is going to be a cold shower.
I'm glad you're doing it; now you'll be a real business. But expect a big backlash and angry customers.
In short, this switch is enough "focus" for now. You'll know when you're out of the woods when the emails fall to a trickle, at which point you can consult these new paying customers about what they need in the next release.
Better yet, collect emails from people who said "I'll only pay if..." and see if you can make some of that come true.