Quick headsup, the latest version of the official iPhone/iPad Mastodon app (v1.5) now has support for post editing.

It may have already updated automatically, but if it hasn't you can make it update manually:

1. Go to the App Store
2. Click on your profile icon in the top right corner 👤
3. Scroll down to see apps waiting for an update, if Mastodon is there click the "Update" button next to it

After you've updated, to edit one of your posts just go to the post, click ⋯ and then Edit.