I do have some suggestions to promote apps with you guys
Here are some suggestions I read from a post recently, I think it will be helpful for you.
1 Optimize the app title and keywords. When people are looking for apps in app store, they prefer to search some keywords like shooting game, office software and etc. Optimize the title of your app’s title and description is the first thing you should do after you have developed your app.
2 Make an explainer video for your app. Making an explainer video is a very cost and effective app marketing strategy, because it constantly increase the conversion rate of your app. 70% of people prefer to purchase or download app after watched a video, they are also more satisfied than those who didn't. Because a video could give the user an effective preview of the app, to help they understand an app before they actually own it. There are many great app explainer video service providers such as Appgovideo.com, Appegges.com and etc.
3. Start a blog. This is free and quite effective as well. You may announce and update the news of your app, your company and your team in your blog and you will be able to build great publicity for your own organization. The reason is simple, every people love stories.