I am considering integrating the Start App sdk into my Android apps since my apps are free and it seems that it is very difficult to sell apps on the Google Play market. The SDK seems very easy to integrate; however, 2 of my apps are for my wife's kindergarten classroom and we are concerned about how intrusive it will be in the app since it is used by 5 & 6 year olds. Any input would be appreciated.

I did use but since then I've moved away from Startapp. It is less intrusive than push ads or pop-ups. Check this post for details https://www.buzztouch.com/forum/thread.php?tid=AF976A17FF7F078FA39E2EC

Startapp is a good ad service and it is totally non-intrusive. Yes, it adds search points in browser and a search icon on the homescreen at start sometimes. But other than that its cool. Have you considered using admob? Its best of all though it pays less considering other ad services.But most of the users will find it ok. I have couple of apps targeted to kids and i use both these ad services in it. I also use Airpush in my other apps and it pays me more than admob or startapp. But i have not used it in the apps targeted to kids for the same reason you are considering. Recently, Scringo has made many new changes in its sdk and now they too pay developers for ads like popup ads and more app tab. They pay developers $25/- per app as a bonus revenue for trying and using their servie. But i am not sure whether you should use this service in apps targeted to kids because it has socializing features which i think is not a good idea for the kids.

Good WRITE UP Sandeep. I to use Scringo's new ad platform, and made a good amount of money the first month with them. I also have Startapp on a couple of apps, but there reporting seems to be off a little to me.

@Yousicc- Yes i totally agree with you on the reporting being off a bit from startapp. The revenue has dropped considerably for last couple of months and if you compare the number of downloads either from DIstimo or Appannie and the startapp console, the startapp console shows less figure of downloads. This might be because startapp counts the downloads only if the users accept the eula terms. Scringos revenue is really more considering any other ad network. For me its been around about $10 ecpm. I too made hundreds of $ in the first month. Thats mostly because i had about 25 apps live with scringo last month.