I’m looking for the best software that can edit Tumblr posts offline, any advice is appreciated.
In iPad or IPhone, use Markdown with Elements , you can use titles, insert graphics and format text. At the end, just copy html from preview.
some edit Tumblr posts in Word, then doing a paste/copy in Notepad to strip out any unwanted formatting.
edit the posts (including Links) in Windows Live Writer (WLW), then copy and paste manually into Tumblr