Tips for marketing an iPhone app

Just finished making the first version of an iPhone app and have started press releasing it. I've found the whole app review thing a bit of a minefield and discovered that app reviews themselves are a business! We're doing the usual social stuff, talks etc and have also tried FB and Google ads. The ads haven't generated enough downloads to justify the expense. Would love any tips on this. The app is https://itunes.apple.com/us/app/the-super-times/id509942440?mt=8 in case you have any market specific advice. Thanks! :)