I'm not 100% sure about iOS products but with the android I have the photobucket app that I can upload pictures to my photobucket account and then simply copy and paste the url into a post.
Yeah I also use the photobucket app. Once you upload a pic to photobucket, you choose the pic and click on "direct link". It automatically copies the link, then you paste it on your message, then add the image tags...
Also, by using photobucket, you can access your pictures from any computer. I've never tried the Tapatalk app, sounds kinda cool.