Everyone thinks, there is only Google Play for publishing android apps. Ofcourse Google Play can bring us a lot more of downloads but why to not use alternative android app stores if we can make it?
Each alternative store is accepting standard .apk with Google Play services (except Amazon store). If you followed my previous tutorials to create .apk and made one with promotional graphics, then you can use it to increase your stats and audience.
Alternative stores where you can send your applications:
Amazon Store - appstore from Amazon, application submission is completly free and you can earn money using Amazon Ads. Also Amazon payments are possible for you to use and get money from microtransactions. However to use Amazon store you need to recreate your APK:
1. Remove admob
2. Remove Google Play Services from your application, Kindle devices haven't this library and will generate Force Close Errors
3. Register on Amazon Developer website, it's free and instant. You can submit now your apk. Acceptance progress may take few days.
My personal experience: apps for kindle phone devices not made a lot of money, maybe 5000 downloads each one but app for Amazon TV (game) made $1900. Good for no effort, upload took maybe 15 minutes. Amazon TV is also good niche because not many games supports Amazon controller. I've added it in Unity3D with free stuff from asset store.
Slideme - old market, I have inside apps from 2011. However installs are not so big, for few years each of my 14 apps got max 10k installs. Maybe I've not made a lot but for sure, 100% I've made a good cash for pizza an beer for few minutes of work. Attention: market is very strict for any blackhat!
Uptdown Market - very good, one of the biggest alternative markets. I am making 10k-50k downloads for each app I am putting on this market. It's accepting apk without any change and screen sizes same as in Google Play. The biggest thing that market is accepting any blackhat apps, mp3 downloaders, movie streams, pirated apps, anything you want. Review time for first submission takes even 7 day but after that you can spam in this market with any apps.
Apptoide - good known, market for pirated apps. You can upload everything, from legal apps to ... minecraft rips. I haven't any success with this market but I see many people are sending minecraft copies with injected ads. They are getting 500k-few millions downloads for these rips. I am not doing it but If you are interested to, you can use: Enhance tool (find in Google), it's free tool to inject apk with any ads without using original keystore.
Getjar - very bad market, if you want you can try but my legal apps are not accepted for ... 2013. People says it's big but I don't belive in Getjar
Chinese markets - there are many Chinese markets you can try to submit your apps. They are not bigger than Google Play, userbase is impressive but you there is a catch. You need to have chinese ID to accept your account. (Hire Chinese citzen). Thats why I've never tried. Chinese market is also specyfic. You need to have app in chinese and using their ads providers. So if you don't know language, it can be difficult to get any money from China.