I just nabbed Xpad and BleachBit from a Debian and a Slackware install to use with my Porteus 5.1 Alpha and thought I'd mention something for newbs who might be interested..
Porteus (and family) have the ability to easily convert most txz, deb, and rpm packages into the Porteus xzm format. If you copy or download say one of these nifty accessories in those formats, an option appears in the file-manager to convert them for use and activation when they are highlighted.
So, theoretically if one is really aching for a repository or app store kept up to date, one might consider installing the typical "scatter disk" distribution, instructing their package manager to "keep" the packages (and not auto clean them out) for use with Porteus or others in the family afterwards with conversion.
And of course, these distros make a super-fine place to put your /porteus folder !!!
Porteus and family are my daily drivers, but this is just one option that might be overlooked if lack of a gonzo-sized app-store has you worried. And of course one might wish to be part of the community of whatever that distro you are using as well.
In fact, I might scatter-disk install Artix for use with any packages not found in Porteus! (Nemesis has it's own related system). See what I'm saying. Porteus is beautiful, man! At any time I might be switching between Porteus, Nemesis proper, or perhaps Artix (or other distro of your choice) itself. All supporting each other!
No App Store? No Problem!
No App Store? No Problem!
That's a UNIX book - cool. -Garth
No App Store? No Problem!
For what it's worth, a few times I have successfully converted packages from Void Linux 

> Does not compute_ 
https://forum.porteus.org/viewtopic.php?p=94310#p94310
https://forum.porteus.org/viewtopic.php?p=102066#p102066
https://forum.porteus.org/viewtopic.php?p=102306#p102306
https://forum.porteus.org/viewtopic.php?p=72741#p72741

https://forum.porteus.org/viewtopic.php?p=94310#p94310
https://forum.porteus.org/viewtopic.php?p=102066#p102066
https://forum.porteus.org/viewtopic.php?p=102306#p102306
https://forum.porteus.org/viewtopic.php?p=72741#p72741