fix grammar and typos

1 files changed, 1 insertions, 1 deletions

diff --git a/13.md b/13.md
index cf28d86..e3662a5 100644
--- a/13.md
+++ b/13.md
@@ -90,4 +90,4 @@ $ echo '["REQ", "subid", {"ids": ["000000000"]}]'  | websocat wss://some-relay.c
 Delegated Proof of Work
 -----------------------
 
-Since the `NIP-01` note id does not commit to any signature, PoW can be outsourced to PoW providers, perhaps for a fee. This provides a way for clients to get their messages out to PoW-restricted relays without having to do any work themselves, which is useful for energy constrained devices like on mobile
+Since the `NIP-01` note id does not commit to any signature, PoW can be outsourced to PoW providers, perhaps for a fee. This provides a way for clients to get their messages out to PoW-restricted relays without having to do any work themselves, which is useful for energy-constrained devices like mobile phones.