I searched for answer, but didn't find it anywhere: why are some app's updates present in Appstore-Updates-Available Updates, but some are not? Can users find updates to your apps there?

They can find updates in the store only if the app developer has submitted one and it's been approved. But, not all updates to your Buzztouch app require a store update...that's the beautiful thing about Buzztouch! Unless you are adding new code, functionality, or in-app content (stuff bundled with the app), then all your updates get pushed directly to your users when you hit the Publish button (assuming you're app was shipped with the config file in Live mode, which is should be). Does this answer your question? Mark

I never found any of my app updates, that were submitted and approved in Available Updates. Did you sure find yours there? Am I doing something wrong?

Either you or somebody who manages your account has to submit updates to the iTunes Store. I only find mine there if I have submitted them. Buzztouch does not submit any updates at all. Mark

Of course I submitted them myself, about 20 times, but users who have my apps installed, don't know that my new update is available. That is the problem and I would like to know if you have same problem or I am doing something wrong.

If you submitted an update, and it was reviewed and approved by Apple (I'm assuming you're talking iOS here), and you indicated you wanted it to be immediately available, then the updates should appear in iTunes shortly after approval. Users will get notified of updates only if they visit the App Store using the App Store App, and going to the Updates section. They won't receive an email or anything like that indicating an update is available. That's how the store basically works. It sounds like what you are seeing is how it's designed to work. Mark

"Users will get notified of updates only if they visit the App Store using the App Store App, and going to the Updates section." That is exactly what I am asking: if user visit AppStore using the AppStore App, my app update is not present there.

I've never seen anybody complain of this in the forum, so it looks like you have an issue that you need to take up with Apple. Mark

Some users have auto-updates enabled. They won't see a list of apps needing updates. Some users are running iOS 7 or iOS 8 or even iOS 6. The Updated apps section in the App Store app will look and behave differently with each version of iOS. -- Niraj

Either way its an Apple issue. People have to have the app installed in order to see the update. Lets say I install you app, a few months later I delete it, if you submit an update after I delete it, i will no be notified. Its the first time I hear about updates not showing up.... weird. Cheers