Are there particular platforms you're thinking of? The big complaint was iOS, which was resolved a while ago. (The legal constraints around the app store are complicated, but basically, Apple does not reject GPL apps. So it merely requires the copyright holders to agree that distribution on the App Store does not infringe their rights under the GPL, which is a reasonable position to take.)
For a library that is GPL, you would need that library's authors to relicense it to allow it on the App Store.
It's not that reasonable: the Apple EULA requires things that directly conflict with the GPL, such as the EULA requiring non-distribution of the binary.