Some wallets like nostr:npub1mutnyacc9uc4t5mmxvpprwsauj5p2qxq95v4a9j0jxl8wnkfvuyque23vg and nostr:npub1dx5q2el8nd4eh3eg9t2e25fd7zuqg7zxz6ldkc3uzgh66ss2yc6st288sj are actual wallets first and foremost though. They just make use of the Nostr social graph to make it easy to pay your frens.