Please do not post the same thing multiple times. The board software automatically flags certain posts as needing moderator attention. This happens the most often for new users. I'm pretty sure this is made clear at the time you attempt to post. Posting the same thing over and over again just makes that many more posts the moderators have to weed through later. This makes us sad. Don't make us sad. If your post/thread doesn't appear, just wait a while. Don't post it again. If it hasn't shown up by the next day, then you can try again. I normally go through posts in the mornings, and try to check a few times throughout the day, but I'm not here 24/7. There will typically be a significant delay before posts are approved. Just be patient.
I recently added this functionality to my fitness app. What you can do is setup a free account with MailChimp and integrate their iOS SDK in your project. With just a few lines of code, you will be able to subscribe users to your list.
You will still need to create a view/popup that shows up when the user launches the app ( add this to your appdelegate to check if the subscription dialog has been shown before or not and then show the view if needed ).
Its definitely working well for me. So far I have collected close to 30 emails and plan to release an eBook by advertising to the folks who have subscribed.