Promoting Android Apps for Free

I always thought that realizing an idea into code was the toughest part of app development. Having completed development and published the app in the Play store, I realize that promoting an app is no mean task. With little or no promotion, the app is just a drop in the ocean in the Play store. More so, if you are offering an app with no ads. In the past few weeks, while I have been trying to publicize my app  for free, I found the following resources useful:

• cpimobi.com gives 50 free installs of your app, thereafter you would be charged per install. This is a good place to start with.
• There are many review exchange sites such as ReviewsMotion and Favorr that help developers review each others' apps. Developers join these sites and list their apps. You select an app to review, use it and publish a review in the Play store. The user whose app was reviewed is notified and does the same. 
• XDA is considered a forum for Android experts. Several developers visit the forum to list and check out apps. You can create a thread and submit your app there 
• Appszoom is an app aggregation site that lists the apps with a good summary page 

• Send out a tweet announcing your app: if you have many followers, then this might be effective 
• Facebook and Google Plus Android groups: there are too many of them, pick the one with the most recent activities and post there
• If you have developed using Android Material design, you can submit it in the Google Plus Material Style Apps group. If you have joined MaterialUp, a site for promoting Material design, listing your app in this group might lead it to be featured in the site. 

Never forget to track threads and comments in the groups and forums where you have your app listed. People hate non-responsive developers who are cold to bugs or feedback.