Thanks Hüseyin for sharing our project!
I'm a co-founder of Sticker.Place. Please contact me directly andrey (at) sticker.place if you have any questions about submitting process.
Great incremental improvement in the sticker submitting process! Takes all the pain of developer profiles, and figuring out the mismatch of certificates and what not!
That's right. We talked with more than 100 artists and nobody of them have an idea of how to submit the sticker pack and they really don't want to think about all these provision profiles, certificates and so on.
It's easy enough to do this yourself if you are interested in it. No need to go via a third party.
Might be nice to go through a third party so you don't have to pay the $99 developer fee (If they post it to the app store for you).