1. contact a Lifehacker writer and offer to: do an interview and give them some 'promo' codes as a 'thank you' for their readers taking a look at your app

2. write a blog post introducing the app, thanking all the new users and lifehacker.

3. spend some money on advertising (facebook/google/maybe even on lifehacker) for two weeks.

4. update something in the app and release a 1.x version update for free. then start working on v2 with the goal of shipping as soon as possible. keep your blog updated on a weekly basis with a simple 'status' of how the new version is coming along, with teasers about new features or speed or whatever.