Here are a couple creative ideas first one you could probably get a dozen or so testers for under $500 (about the cost of a decent adwords test campaign). The other one you can do for absolutely free if you use your time. I have done both, and still do for my own projects, and they work tremendously well.
- Creative Outsourcing. Go where your audience is--there are a lot of ios and html5 developers who have profiles and do a surprising large amount of business on outsourcing sites.
Use outsourcing sites to pay small fees to test this for a week at a time. You should be able to get this done cheap if you use a quality headline and the right tags for your job.
--To learn about this Noah Kagan of Appsumo.com (I have no direct association to the site) Noah made a great video on hiring interns there is some great advice in that video when it comes to writing a "stand out from the crowd" hiring add. It was on hiring interns but the same concepts apply.--
The key for you is to position the job so that the developers are inclined to help because of the quality of your project and the excitement of being part of it, rather than purely monetary compensation.
There are the obvious few:
- Go where the people who know the developers are. Forums are a good place to look, we are here with like minded people asking and answering questions about entrepreneurship and startups. Do the same for Iphone developers
a. go to:
b. locate niche specific forums (iphone development) with a large membership
c. get active in a few discussions-- genuine participation surrounding similar topics to what you are looking to have beta tested.
d. find posts related to your idea in some way, and look for the most active participants, send them a friendly message and ask them for help or if they would like to some how be involved.
e. If you really enjoy the forum and become active start a thread with an exciting headline, copy the style and language of other successful threads on the forum.
In my experience people in general like to help when our intentions are pure and we are trying to introduce something good in the right community.
Hope that helps