For developers, it could be a good source of extra income. That said, some developers have reported huge download numbers off the back of the free app of the day promotion, but no resulting increase in sales once the promotion is over. You are also likely to do better with tablet optimized apps than smartphone apps in general, as Kindle users are the primary customers. Droid App
If you are seeking an alternative app store because you find the Play Store overwhelming and difficult to search, then we have another solution to suggest. You could try an app that’s designed to improve the app discovery process and aid you in finding the content you want, but that still ultimately plugs into the Play Store to download and install apps and games. Droid App