Improved trade is one of the major benefits of being in an fellowship. To achieve this improvement, every member accepts trade offers from their fellows before taking trades from outside or posting offers.
On mobile, its very annoying (up to chaper 11) or even next to impossible (chapters 12+) to find offers from other members of your clan.
Instead of having the essential "FS only" filter the mobile version offers a totally useless "No fee" option. This has been brought up multiple times, but the devs refuse to do anything about it.