I really like the stickers I got with my Kagi t-shirt, so why not add them as iOS stickers as well? This would let iOS users rep Kagi digitally and help spread the word. iOS sticker packs are very easy to create, so this would require little development time for what I think could be a great reward.
The sticker pack should include versions of the physical stickers, as well as the typical Doggo branding such as the swirl and the one on the homepage. Additional stickers could include some simple emoticon-style Doggo expressions, and could include slogans and call-to-actions (such as "Humanise the Web"). Stickers could be done in-house or possibly community-sourced (I'd love to contribute some). I don't use Android messaging apps but I believe some may have sticker capability as well?
